A programmable combination lock with keyed lock override is disclosed. The lock employs a stack of rings and dial wheels, with a mechanism for coupling and decoupling the rings and dial wheels. A user can program a custom code by unlocking the combination and rotating the inner and outer dial wheels until the desired code is indicated, and then locking the combination lock to set the code. A keyed lock with a master key couples to the combination lock and can override a combination lock in the locked state. The keyed lock allows multiple keys to lock and unlock the combination lock. In the event that a user loses the master key, the user can use the second key to create a new lock combination to operate the lock, yet render the lost master key inoperable.