The term Custodian may refer to:
- Janitor, a person who cleans and maintains buildings
- Custodian bank, an organization responsible for safeguarding a firm's or individual's financial assets.
- Custodian helmet, the helmet worn by many members of the British Police Force
- A legal guardian or conservator may be called a custodian in some jurisdictions
MC, air warden, attendant, attorney, bailiff, bull, butler, caretaker, castellan, cerberus, char, charwoman, cleaner, cleaner-off, cleaner-up, cleaning lady, cleaning man, cleaning woman, commandant, conservator, croupier, curator, custos, emcee, factor, forest ranger, game warden, gamekeeper, gaoler, governor, guard, guardian, guardian angel, housekeeper, jailer, janitor, janitress, keeper, landreeve, librarian, lifeguard, lifesaver, majordomo, master of ceremonies, next friend, overseer, principal keeper, prison guard, prochein ami, proctor, procurator, ranger, screw, seneschal, shepherd, steward, supervisor, turnkey, warden, warder, watchdog