diff --git a/scripts/detect_unused_scripts.py b/scripts/detect_unused_scripts.py
new file mode 100644
index 00000000..88a6000f
--- /dev/null
+++ b/scripts/detect_unused_scripts.py
@@ -0,0 +1,68 @@
+"""Detect scripts not referenced by Makefile, CI, or docs."""
+
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+REFERENCE_FILES = ["Makefile", ".github/workflows/ci.yml", "docs/PROJECT_INDEX.md", "AGENTS.md"]
+
+EXEMPT = {"scripts/__init__.py", "scripts/check_doc_links.py", "scripts/safety/check_claims.py"}
+
+
+def detect_unused(scripts_dir: str = "scripts") -> dict:
+    root = Path(scripts_dir)
+    if not root.exists():
+        return {"error": f"Directory not found: {scripts_dir}"}
+
+    # Collect all .py scripts
+    all_scripts = sorted(f.relative_to(root.parent) for f in root.rglob("*.py") if f.name != "__init__.py")
+
+    # Collect all script names from reference files
+    referenced_names: set[str] = set()
+    for ref_path in REFERENCE_FILES:
+        rp = Path(ref_path)
+        if rp.exists():
+            text = rp.read_text()
+            for s in all_scripts:
+                if s.name in text or str(s) in text:
+                    referenced_names.add(str(s))
+
+    referenced = sorted(referenced_names)
+    unreferenced = sorted(set(str(s) for s in all_scripts) - referenced_names - EXEMPT)
+
+    return {
+        "scripts_dir": scripts_dir,
+        "total_scripts": len(all_scripts),
+        "referenced": len(referenced),
+        "unreferenced": len(unreferenced),
+        "exempt": len(EXEMPT),
+        "detailed": {
+            "referenced": referenced,
+            "unreferenced": unreferenced,
+            "exempt": sorted(EXEMPT),
+        },
+    }
+
+
+def main() -> int:
+    result = detect_unused()
+    if "error" in result:
+        print(result["error"], file=sys.stderr)
+        return 2
+
+    print(f"Total scripts: {result['total_scripts']}")
+    print(f"Referenced: {result['referenced']}")
+    print(f"Unreferenced: {result['unreferenced']}")
+    print(f"Exempt: {result['exempt']}")
+
+    if result["unreferenced"]:
+        print("\nUnreferenced scripts:")
+        for s in result["detailed"]["unreferenced"]:
+            print(f"  ❌ {s}")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/tests/test_detect_unused_scripts.py b/tests/test_detect_unused_scripts.py
new file mode 100644
index 00000000..bfe7ee65
--- /dev/null
+++ b/tests/test_detect_unused_scripts.py
@@ -0,0 +1,25 @@
+"""Tests for unused script detector."""
+from scripts.detect_unused_scripts import detect_unused
+
+
+def test_detector_runs():
+    r = detect_unused()
+    assert "total_scripts" in r
+    assert r["total_scripts"] > 0
+
+
+def test_referenced_count_is_int():
+    r = detect_unused()
+    assert isinstance(r["referenced"], int)
+
+
+def test_unreferenced_count_is_int():
+    r = detect_unused()
+    assert isinstance(r["unreferenced"], int)
+
+
+def test_no_negative_counts():
+    r = detect_unused()
+    assert r["referenced"] >= 0
+    assert r["unreferenced"] >= 0
+    assert r["exempt"] >= 0