diff --git a/app/Connect/Actions/AwardAchievementAction.php b/app/Connect/Actions/AwardAchievementAction.php
index b55021ae15..1fa059364b 100644
--- a/app/Connect/Actions/AwardAchievementAction.php
+++ b/app/Connect/Actions/AwardAchievementAction.php
@@ -14,6 +14,7 @@
 use App\Models\PlayerGame;
 use App\Models\StaticData;
 use App\Models\User;
+use App\Platform\Actions\ResumePlayerSessionAction;
 use App\Platform\Jobs\UnlockPlayerAchievementJob;
 use Illuminate\Http\Request;
 use Illuminate\Support\Carbon;
@@ -167,6 +168,19 @@ protected function process(): array
             return $this->unsupportedSystem('Cannot unlock achievements for unsupported console.');
         }
 
+        $playerSession = app()->make(ResumePlayerSessionAction::class)->execute(
+            $this->user,
+            $this->achievement->game,
+            ($this->gameHash && !$this->gameHash->isMultiDiscGameHash()) ? $this->gameHash : null,
+            timestamp: $this->when,
+            userAgent: $this->userAgent,
+            ipAddress: $this->ipAddress,
+        );
+
+        if ($this->connectWarning) {
+            $this->connectWarning->player_session_id = $playerSession->id;
+        }
+
         $playerGame = PlayerGame::query()
             ->where('user_id', $this->user->id)
             ->where('game_id', $this->achievement->game_id)
diff --git a/app/Connect/Support/GeneratesConnectWarnings.php b/app/Connect/Support/GeneratesConnectWarnings.php
index 400190dbd0..ab1b21a7dc 100644
--- a/app/Connect/Support/GeneratesConnectWarnings.php
+++ b/app/Connect/Support/GeneratesConnectWarnings.php
@@ -8,8 +8,11 @@
 use App\Models\ConnectWarning;
 use App\Models\Game;
 use App\Platform\Services\UserAgentService;
+use App\Support\Alerts\SuspiciousConnectWarningAlert;
+use Carbon\Carbon;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Cache;
 
 trait GeneratesConnectWarnings
 {
@@ -23,6 +26,7 @@ public function handleRequest(Request $request): JsonResponse
         if ($this->connectWarning !== null) {
             $this->finalizeWarning();
             $this->connectWarning->save();
+            $this->sendNotifications();
         }
 
         return $result;
@@ -87,4 +91,17 @@ private function finalizeWarning(): void
             }
         }
     }
+
+    private function sendNotifications(): void
+    {
+        if (str_contains($this->connectWarning->smells, 'repeated_validation')
+            || str_contains($this->connectWarning->smells, 'wrong_client')) {
+
+            // only send one notification per user per day
+            $key = 'user:' . strtolower($this->connectWarning->username) . ':connect_warning_notification';
+            if (Cache::add($key, '1', Carbon::now()->addDay())) {
+                (new SuspiciousConnectWarningAlert($this->connectWarning))->send();
+            }
+        }
+    }
 }
diff --git a/app/Support/Alerts/SuspiciousConnectWarningAlert.php b/app/Support/Alerts/SuspiciousConnectWarningAlert.php
new file mode 100644
index 0000000000..3a27a47224
--- /dev/null
+++ b/app/Support/Alerts/SuspiciousConnectWarningAlert.php
@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Support\Alerts;
+
+use App\Models\Achievement;
+use App\Models\ConnectWarning;
+use App\Models\Game;
+use App\Models\Leaderboard;
+use App\Models\User;
+
+class SuspiciousConnectWarningAlert extends Alert
+{
+    public function __construct(
+        public readonly ConnectWarning $warning,
+    ) {
+    }
+
+    public function toDiscordMessage(): string
+    {
+        $user = User::whereName($this->warning->username)->firstOrFail();
+
+        $gameId = match ($this->warning->method) {
+            'submitlbentry' => Leaderboard::find($this->warning->related_id)?->game_id,
+            default => Achievement::find($this->warning->related_id)?->game_id,
+        };
+
+        if ($gameId) {
+            // repeated_validation takes precedence
+            if (str_contains($this->warning->smells, 'repeated_validation')) {
+                return $this->repeatedValidationDiscordMessage($user, $gameId);
+            }
+
+            if (str_contains($this->warning->smells, 'wrong_client')) {
+                return $this->wrongClientDiscordMessage($user, $gameId);
+            }
+        }
+
+        return "";
+    }
+
+    /**
+     * "[Scott](<https://retroachievements.org/user/Scott>) unlocked [Sonic the Hedgehog](<https://retroachievements.org/game/1>) achievements using PPSSPP - [Activity](<https://retroachievements.org/user/Scott/game/1/activity>)"
+     */
+    private function wrongClientDiscordMessage(User $user, int $gameId): string
+    {
+        $playerUrl = route('user.show', ['user' => $user]);
+
+        $game = Game::findOrFail($gameId);
+        $gameUrl = route('game.show', ['game' => $game]);
+
+        $activityUrl = route('user.game.activity.show', ['user' => $user, 'game' => $game]);
+
+        return sprintf(
+            match ($this->warning->method) {
+                'submitlbentry' => '[%s](<%s>) submitted [%s](<%s>) leaderboard entries using %s - [Activity](<%s>)',
+                default => '[%s](<%s>) unlocked [%s](<%s>) achievements using %s - [Activity](<%s>)',
+            },
+            $user->display_name,
+            $playerUrl,
+            $game->title,
+            $gameUrl,
+            $this->warning->user_agent,
+            $activityUrl,
+        );
+    }
+
+    /**
+     * "[Scott](<https://retroachievements.org/user/Scott>) used the same incorrect validation hash for multiple unlocks - [Activity](<https://retroachievements.org/user/Scott/game/1/activity>)"
+     */
+    private function repeatedValidationDiscordMessage(User $user, int $gameId): string
+    {
+        $playerUrl = route('user.show', ['user' => $user]);
+        $activityUrl = route('user.game.activity.show', ['user' => $user, 'game' => $gameId]);
+
+        return sprintf(
+            '[%s](<%s>) used the same incorrect validation hash for multiple unlocks - [Activity](<%s>)',
+            $user->display_name,
+            $playerUrl,
+            $activityUrl,
+        );
+    }
+}
diff --git a/tests/Feature/Connect/AwardAchievementTest.php b/tests/Feature/Connect/AwardAchievementTest.php
index 3984052802..2c5b8a5eaf 100644
--- a/tests/Feature/Connect/AwardAchievementTest.php
+++ b/tests/Feature/Connect/AwardAchievementTest.php
@@ -19,8 +19,10 @@
 use App\Models\System;
 use App\Models\User;
 use App\Platform\Enums\UnlockMode;
+use App\Support\Alerts\Jobs\SendAlertWebhookJob;
 use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
 use Illuminate\Support\Carbon;
+use Illuminate\Support\Facades\Queue;
 use Illuminate\Support\Str;
 use Tests\Feature\Concerns\TestsEmulatorUserAgent;
 use Tests\Feature\Platform\Concerns\TestsPlayerAchievements;
@@ -149,6 +151,12 @@ public static function getWarning(Achievement $achievement): ConnectWarning
             ->whereNull('extra')
             ->first();
     }
+
+    public static function initializeFakeQueue(): void
+    {
+        Queue::fake([SendAlertWebhookJob::class]);
+        config(['services.discord.alerts_webhook.suspicious_connect_warning' => 'https://discord.com/api/webhooks/test']);
+    }
 }
 
 beforeEach(function () {
@@ -2487,6 +2495,8 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $unlock1Date = $now->clone()->subMinutes(65);
         $this->addHardcoreUnlock($this->user, $achievement1, $unlock1Date, $gameHash);
 
+        AwardAchievementTestHelpers::initializeFakeQueue();
+
         // $userAgentValid is associated to the "Test Client". Attach a differing system to that.
         $otherSystem = System::factory()->create();
         Emulator::where('name', 'Test Client')->first()->systems()->attach($otherSystem->id);
@@ -2530,6 +2540,11 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $this->assertEquals($validationHash, $warning->validation_hash);
         $this->assertEquals('wrong_client', $warning->smells);
         $this->assertEquals($this->userAgentValid, $warning->user_agent);
+
+        // notification should be sent
+        Queue::assertPushedOn('alerts', SendAlertWebhookJob::class, function ($job) {
+            return $job->webhookUrl === 'https://discord.com/api/webhooks/test';
+        });
     });
 
     test('user agent for incorrect system on multi-system client does not generate warning', function () {
@@ -2647,6 +2662,8 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $unlock1Date = $now->clone()->subMinutes(65);
         $this->addHardcoreUnlock($this->user, $achievement1, $unlock1Date, $gameHash);
 
+        AwardAchievementTestHelpers::initializeFakeQueue();
+
         // do the hardcore unlock
         $validationHash = md5('This is the wrong validation hash');
         $scoreBefore = $this->user->points_hardcore;
@@ -2686,6 +2703,9 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $this->assertEquals($validationHash, $warning->validation_hash);
         $this->assertEquals('bad_validation', $warning->smells);
         $this->assertEquals($this->userAgentValid, $warning->user_agent);
+
+        // notification should not be sent
+        Queue::assertNotPushed(SendAlertWebhookJob::class);
     });
 
     test('validation hash containing 0 offset still unlocks hardcore achievements', function () {
@@ -2795,6 +2815,8 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $unlock1Date = $now->clone()->subMinutes(65);
         $this->addHardcoreUnlock($this->user, $achievement1, $unlock1Date, $gameHash);
 
+        AwardAchievementTestHelpers::initializeFakeQueue();
+
         // do the hardcore unlock
         $validationHash = md5('This is the wrong validation hash');
         $scoreBefore = $this->user->points_hardcore;
@@ -2845,5 +2867,84 @@ public static function getWarning(Achievement $achievement): ConnectWarning
         $this->assertEquals($validationHash, $warning->validation_hash);
         $this->assertEquals('bad_validation,repeated_validation', $warning->smells);
         $this->assertEquals($this->userAgentValid, $warning->user_agent);
+
+        // notification should be sent
+        Queue::assertPushedOn('alerts', SendAlertWebhookJob::class, function ($job) {
+            return $job->webhookUrl === 'https://discord.com/api/webhooks/test';
+        });
+    });
+
+    test('only one warning notification per user per day', function () {
+        $data = AwardAchievementTestHelpers::createGame();
+        $game = $data['game'];
+        $achievement1 = $data['achievements'][0];
+        $achievement3 = $data['achievements'][2];
+        $achievement4 = $data['achievements'][3];
+        $gameHash = $data['gameHash'];
+        $now = Carbon::now();
+
+        $unlock1Date = $now->clone()->subMinutes(65);
+        $this->addHardcoreUnlock($this->user, $achievement1, $unlock1Date, $gameHash);
+
+        AwardAchievementTestHelpers::initializeFakeQueue();
+
+        // do the hardcore unlock
+        $validationHash = md5('This is the wrong validation hash');
+        $scoreBefore = $this->user->points_hardcore;
+        $softcoreScoreBefore = $this->user->points;
+        $truePointsBefore = $this->user->points_weighted;
+
+        ConnectWarning::create([
+            'method' => 'awardachievement',
+            'username' => $this->user->username,
+            'related_type' => 'achievement',
+            'related_id' => $achievement1->id,
+            'hardcore' => 1,
+            'validation_hash' => $validationHash,
+            'smells' => 'bad_validation',
+            'user_agent' => $this->userAgentValid,
+        ]);
+
+        $this->withHeaders(['User-Agent' => $this->userAgentValid])
+            ->get($this->apiUrl('awardachievement', [
+                'a' => $achievement3->id,
+                'h' => 1,
+                'm' => $gameHash->md5,
+                'v' => $validationHash,
+            ]))
+            ->assertStatus(200)
+            ->assertExactJson([
+                'Success' => true,
+                'AchievementID' => $achievement3->id,
+                'AchievementsRemaining' => 4,
+                'Score' => $scoreBefore + $achievement3->points,
+                'SoftcoreScore' => $softcoreScoreBefore,
+            ]);
+
+        // notification should be sent
+        Queue::assertPushedOn('alerts', SendAlertWebhookJob::class, function ($job) {
+            return $job->webhookUrl === 'https://discord.com/api/webhooks/test';
+        });
+
+        AwardAchievementTestHelpers::initializeFakeQueue();
+
+        $this->withHeaders(['User-Agent' => $this->userAgentValid])
+            ->get($this->apiUrl('awardachievement', [
+                'a' => $achievement4->id,
+                'h' => 1,
+                'm' => $gameHash->md5,
+                'v' => $validationHash,
+            ]))
+            ->assertStatus(200)
+            ->assertExactJson([
+                'Success' => true,
+                'AchievementID' => $achievement4->id,
+                'AchievementsRemaining' => 3,
+                'Score' => $scoreBefore + $achievement3->points + $achievement4->points,
+                'SoftcoreScore' => $softcoreScoreBefore,
+            ]);
+
+        // notification should not be sent
+        Queue::assertNotPushed(SendAlertWebhookJob::class);
     });
 });
diff --git a/tests/Feature/Support/Alerts/SuspiciousConnectWarningAlertTest.php b/tests/Feature/Support/Alerts/SuspiciousConnectWarningAlertTest.php
new file mode 100644
index 0000000000..c1c3b3ce73
--- /dev/null
+++ b/tests/Feature/Support/Alerts/SuspiciousConnectWarningAlertTest.php
@@ -0,0 +1,157 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Support\Alerts;
+
+use App\Models\Achievement;
+use App\Models\ConnectWarning;
+use App\Models\Game;
+use App\Models\Leaderboard;
+use App\Models\System;
+use App\Models\User;
+use App\Support\Alerts\Jobs\SendAlertWebhookJob;
+use App\Support\Alerts\SuspiciousConnectWarningAlert;
+use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
+use Illuminate\Support\Facades\Queue;
+use Tests\TestCase;
+
+class SuspiciousConnectWarningAlertTest extends TestCase
+{
+    use LazilyRefreshDatabase;
+
+    public function testToWrongClientDiscordMessageFormatsCorrectlyForAchievement(): void
+    {
+        // Arrange
+        $system = System::factory()->create();
+        $user = User::factory()->create(['username' => 'Scott', 'display_name' => 'Scott']);
+        $game = Game::factory()->create(['title' => 'Sonic the Hedgehog', 'system_id' => $system->id]);
+        $achievement = Achievement::factory()->create(['game_id' => $game->id]);
+
+        $validationHash = md5($achievement->id . $user->display_name . '1');
+        $warning = new ConnectWarning([
+            'method' => 'awardachievement',
+            'username' => $user->display_name,
+            'user_agent' => 'TestUserAgent/1.0',
+            'validation_hash' => $validationHash,
+            'related_type' => 'achievement',
+            'related_id' => $achievement->id,
+            'hardcore' => 1,
+            'smells' => 'wrong_client',
+        ]);
+        $alert = new SuspiciousConnectWarningAlert($warning);
+
+        // Act
+        $message = $alert->toDiscordMessage();
+
+        // Assert
+        $this->assertStringContainsString('Scott', $message);
+        $this->assertStringContainsString('Sonic the Hedgehog', $message);
+        $this->assertStringContainsString('TestUserAgent', $message);
+        $this->assertStringContainsString('achievements', $message);
+        $this->assertStringContainsString(route('user.show', ['user' => $user]), $message);
+        $this->assertStringContainsString(route('game.show', ['game' => $game]), $message);
+        $this->assertStringContainsString(route('user.game.activity.show', ['user' => $user, 'game' => $game]), $message);
+    }
+
+    public function testToWrongClientDiscordMessageFormatsCorrectlyForLeaderboard(): void
+    {
+        // Arrange
+        $system = System::factory()->create();
+        $user = User::factory()->create(['username' => 'Scott', 'display_name' => 'Scott']);
+        $game = Game::factory()->create(['title' => 'Sonic the Hedgehog', 'system_id' => $system->id]);
+        $leaderboard = Leaderboard::factory()->create(['game_id' => $game->id]);
+
+        $validationHash = md5($leaderboard->id . $user->display_name . '1234');
+        $warning = new ConnectWarning([
+            'method' => 'submitlbentry',
+            'username' => $user->display_name,
+            'user_agent' => 'TestUserAgent/1.0',
+            'validation_hash' => $validationHash,
+            'related_type' => 'leaderboard',
+            'related_id' => $leaderboard->id,
+            'extra' => 1234,
+            'smells' => 'wrong_client',
+        ]);
+        $alert = new SuspiciousConnectWarningAlert($warning);
+
+        // Act
+        $message = $alert->toDiscordMessage();
+
+        // Assert
+        $this->assertStringContainsString('Scott', $message);
+        $this->assertStringContainsString('Sonic the Hedgehog', $message);
+        $this->assertStringContainsString('TestUserAgent', $message);
+        $this->assertStringContainsString('leaderboard entries', $message);
+        $this->assertStringContainsString(route('user.show', ['user' => $user]), $message);
+        $this->assertStringContainsString(route('game.show', ['game' => $game]), $message);
+        $this->assertStringContainsString(route('user.game.activity.show', ['user' => $user, 'game' => $game]), $message);
+    }
+
+    public function testToRepeatedValidationDiscordMessageFormatsCorrectlyForAchievement(): void
+    {
+        // Arrange
+        $system = System::factory()->create();
+        $user = User::factory()->create(['username' => 'Scott', 'display_name' => 'Scott']);
+        $game = Game::factory()->create(['title' => 'Sonic the Hedgehog', 'system_id' => $system->id]);
+        $achievement = Achievement::factory()->create(['game_id' => $game->id]);
+
+        $validationHash = md5($achievement->id . $user->display_name . '1');
+        $warning = new ConnectWarning([
+            'method' => 'awardachievement',
+            'username' => $user->display_name,
+            'user_agent' => 'TestUserAgent/1.0',
+            'validation_hash' => $validationHash,
+            'related_type' => 'achievement',
+            'related_id' => $achievement->id,
+            'hardcore' => 1,
+            'smells' => 'repeated_validation',
+        ]);
+        $alert = new SuspiciousConnectWarningAlert($warning);
+
+        // Act
+        $message = $alert->toDiscordMessage();
+
+        // Assert
+        $this->assertStringContainsString('Scott', $message);
+        $this->assertStringContainsString('same incorrect validation', $message);
+        $this->assertStringContainsString(route('user.show', ['user' => $user]), $message);
+        $this->assertStringContainsString(route('user.game.activity.show', ['user' => $user, 'game' => $game]), $message);
+    }
+
+    public function testSendDispatchesJobWhenWebhookUrlExists(): void
+    {
+        // Arrange
+        Queue::fake();
+
+        config(['services.discord.alerts_webhook.suspicious_connect_warning' => 'https://discord.com/api/webhooks/test']);
+
+        $system = System::factory()->create();
+        $user = User::factory()->create();
+        $game = Game::factory()->create(['system_id' => $system->id]);
+        $achievement = Achievement::factory()->create(['game_id' => $game->id]);
+
+        $validationHash = md5($achievement->id . $user->display_name . '1');
+        $warning = new ConnectWarning([
+            'method' => 'awardachievement',
+            'username' => $user->display_name,
+            'user_agent' => 'TestUserAgent/1.0',
+            'validation_hash' => $validationHash,
+            'related_type' => 'achievement',
+            'related_id' => $achievement->id,
+            'hardcore' => 1,
+            'smells' => 'wrong_client',
+        ]);
+        $alert = new SuspiciousConnectWarningAlert($warning);
+
+        // Act
+        $result = $alert->send();
+
+        // Assert
+        $this->assertTrue($result);
+
+        Queue::assertPushedOn('alerts', SendAlertWebhookJob::class, function ($job) {
+            return $job->webhookUrl === 'https://discord.com/api/webhooks/test';
+        });
+    }
+}