diff --git a/src/BootApp.ts b/src/BootApp.ts
index 92ec596..4aba8a6 100644
--- a/src/BootApp.ts
+++ b/src/BootApp.ts
@@ -5,7 +5,7 @@ import * as vscode from "vscode";
 import { dashboard } from "./global";
 import { requestWorkspaceSymbols } from "./models/stsApi";
 import { ClassPathData, MainClassData } from "./types/jdtls";
-import { isActuatorJarFile, isAlive } from "./utils";
+import { excludeTestMainClasses, isActuatorJarFile, isAlive } from "./utils";
 import { BootAppItem } from "./views/items/BootAppItem";
 import * as lsp from "vscode-languageclient";
 import * as async from "async";
@@ -187,6 +187,19 @@ export class BootApp {
         return this.mainClasses;
     }
 
+    /**
+     * The main classes offered to the user when running/debugging this app, i.e. all
+     * resolved main classes except the ones located in test source folders.
+     *
+     * Falls back to the full list when every main class is in a test source folder, so
+     * that a project whose only main class lives there stays launchable.
+     */
+    public async getLaunchableMainClasses(): Promise<MainClassData[]> {
+        const mainClasses = await this.getMainClasses();
+        const launchable = excludeTestMainClasses(mainClasses, this.classpath);
+        return launchable.length > 0 ? launchable : mainClasses;
+    }
+
     /**
      * getWorkspaceSymbols
      */
diff --git a/src/LocalAppController.ts b/src/LocalAppController.ts
index b577774..4ca7918 100644
--- a/src/LocalAppController.ts
+++ b/src/LocalAppController.ts
@@ -45,7 +45,7 @@ export class LocalAppController {
         const mainClasData = await vscode.window.withProgress(
             { location: vscode.ProgressLocation.Window, title: `Resolving main classes for ${app.name}...` },
             async () => {
-                const mainClassList = await app.getMainClasses();
+                const mainClassList = await app.getLaunchableMainClasses();
 
                 if (mainClassList && mainClassList instanceof Array && mainClassList.length > 0) {
                     return mainClassList.length === 1 ? mainClassList[0] :
diff --git a/src/types/jdtls.d.ts b/src/types/jdtls.d.ts
index fa0548a..94e7de3 100644
--- a/src/types/jdtls.d.ts
+++ b/src/types/jdtls.d.ts
@@ -15,4 +15,5 @@ interface CPE {
     sourceContainerUrl: string;
     javadocContainerUrl: string;
     isSystem: boolean;
+    isTest: boolean;
 }
diff --git a/src/utils.ts b/src/utils.ts
index 2029a72..e009727 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -4,6 +4,7 @@
 import * as path from "path";
 import { Readable } from "stream";
 import * as vscode from "vscode";
+import { ClassPathData, MainClassData } from "./types/jdtls";
 import pidtree = require("pidtree");
 
 export function readAll(input: Readable): Promise<string> {
@@ -48,6 +49,39 @@ export function isActuatorJarFile(f: string): boolean {
     return false;
 }
 
+/**
+ * Whether `filePath` is located inside `folder`. Both are expected to be
+ * absolute file system paths.
+ */
+function isInFolder(filePath: string, folder: string): boolean {
+    const relative = path.relative(folder, filePath);
+    // An empty result means both point at the same location, ".." means filePath
+    // is outside, and an absolute result means they are on different drives.
+    return !!relative && !relative.startsWith("..") && !path.isAbsolute(relative);
+}
+
+/**
+ * Drops the main classes that live in a test source folder of the project.
+ *
+ * `vscode.java.resolveMainClass` searches all source folders, so a
+ * `@SpringBootApplication` class copied into `src/test/java` (a common pattern for
+ * integration tests) shows up as an additional candidate to launch. Those classes
+ * are not what users want to run from the dashboard, and offering them turns a
+ * one-click "run" into a quick pick with irrelevant choices.
+ *
+ * See https://github.com/microsoft/vscode-spring-boot-dashboard/issues/420
+ */
+export function excludeTestMainClasses(mainClasses: MainClassData[], classpath: ClassPathData): MainClassData[] {
+    const testSourceFolders = (classpath?.entries ?? [])
+        .filter(cpe => cpe.kind === "source" && cpe.isTest)
+        .map(cpe => cpe.path);
+    if (testSourceFolders.length === 0) {
+        return mainClasses;
+    }
+    // Keep entries without a file path: they cannot be located, so they cannot be ruled out.
+    return mainClasses.filter(mc => !mc.filePath || !testSourceFolders.some(folder => isInFolder(mc.filePath, folder)));
+}
+
 /**
  * Construct URL based on format defined in spring.dashboard.openUrl
  *
diff --git a/test/suite/extension.test.ts b/test/suite/extension.test.ts
index 1178e87..00c3413 100644
--- a/test/suite/extension.test.ts
+++ b/test/suite/extension.test.ts
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 import * as assert from "assert";
+import * as path from "path";
 import * as vscode from "vscode";
 import { AppState } from "../../src/BootApp";
 import { initSymbols } from "../../src/controllers/SymbolsController";
@@ -69,6 +70,30 @@ suite("Extension Test Suite", () => {
         assert.strictEqual(openedEditor?.selection.anchor.character, 1, "The definition of CrashController should be at character 1.");
     }).timeout(300 * 1000 /** ms */);
 
+    test("Should not offer main classes from test source folders", async () => {
+        let apps = dashboard.appsProvider.manager.getAppList();
+        while (apps.length === 0) {
+            console.log("waiting until the app list is populated");
+            await sleep(5 * 1000 /** ms */);
+            apps = dashboard.appsProvider.manager.getAppList();
+        }
+        const app = apps[0];
+
+        // petclinic declares a main method in PetClinicApplication plus three more in
+        // src/test/java (MysqlTestApplication, PetClinicIntegrationTests, PostgresIntegrationTests).
+        const allMainClasses = await app.getMainClasses();
+        const testMainClasses = allMainClasses.filter(c => c.filePath.includes(path.join("src", "test", "java")));
+        assert.ok(testMainClasses.length > 0, `There should be main classes in test source folders, but got ${JSON.stringify(allMainClasses)}.`);
+
+        // Only the one in src/main/java is a launch candidate. https://github.com/microsoft/vscode-spring-boot-dashboard/issues/420
+        const launchable = await app.getLaunchableMainClasses();
+        assert.deepStrictEqual(
+            launchable.map(c => c.mainClass),
+            ["org.springframework.samples.petclinic.PetClinicApplication"],
+            "Only the main class in src/main/java should be launchable."
+        );
+    }).timeout(300 * 1000 /** ms */);
+
     test("Can view dynamic beans and mappings", async function() {
         // Skip on CI — launching the app is unreliable in headless environments
         // (wmic ENOENT on Windows Server 2025, debug session failures on Linux/macOS).
@@ -81,8 +106,8 @@ suite("Extension Test Suite", () => {
         assert.strictEqual(apps.length, 1, "There are 1 app in the app list.");
         const app = apps[0];
 
-        // Filter to PetClinicApplication to avoid QuickPick when multiple main classes exist
-        app.mainClasses = app.mainClasses?.filter(c => c.mainClass.includes("PetClinicApplication"));
+        // No QuickPick is expected: petclinic's other main classes all live in test
+        // source folders, so PetClinicApplication is the only launch candidate.
         await vscode.commands.executeCommand("spring-boot-dashboard.localapp.run", app);
         while (app.state !== AppState.RUNNING) {
             await sleep(5 * 1000 /** ms */);