Organizes notes. It has no folder password control.
Direct answer
You cannot lock an entire folder in Apple Notes. Apple provides a lock for eligible individual notes. For a folder-like workflow, create a folder, move sensitive notes into it, then lock each eligible note separately. If you need one authentication gate around a whole collection, consider locking the Notes app on a supported iPhone or using a separate secure-storage app.
Protection planner
What are you trying to protect?
Folder appearance is not a security boundary
Protects the eligible note body. Its title remains visible in the list.
Adds device-local authentication before Notes opens on supported iOS versions.
Best native setup
Use a plainly named folder, lock each sensitive note, close Notes when finished, and keep your device passcode private. Test the workflow with a non-sensitive note before moving important material.
