What is the name of the spell that opens locks?

The spell that opens locks is Alohomora. In the Harry Potter series, it is commonly called the Unlocking Charm and is used to open doors, windows, and other locked objects. Hermione Granger first uses it in Harry Potter and the Philosopher's Stone to open the door guarding Fluffy and the trapdoor beneath it.

Alohomora is not universally effective: magical protections can be placed on locks to prevent the charm from working. This is why some doors in Hogwarts and other secure locations require different methods or cannot be opened with the standard spell. The charm is also distinct from Accio, which summons an object toward the caster, and Lumos, which creates wand light.

The spell's unusual name is associated with a West African dialect and is often explained as meaning “friendly to thieves.” In the books, it is a practical piece of magic learned relatively early, but its usefulness depends on the strength and enchantments of the lock.