The present invention provides a handlebar locking mechanism and a handlebar locking device, each of which (i) can be used for a moving body whose traveling direction is changed with a handlebar and (ii) which makes it difficult to unlock the handlebar by a forcible method such as breaking. The handlebar locking device (20) includes an engagement hole (11c) made in a steering column (11a), a lock pin (31) which locks a handlebar (5) in a case where a pin tip part (31a) of the lock pin (31) is engaged with the engagement hole (11c), and a lock pin drive mechanism which (i) moves, in a case where the handlebar (5) is to be locked, the lock pin (31) so that the pin tip part (31a) is engaged with the engagement hole (11c) and (ii) moves, in a case where the handlebar (5) is to be unlocked, the lock pin (31) so that the pin tip part (31a) is removed from the engagement hole (11c). The engagement hole (11c), the lock pin (31), and the lock pin drive mechanism being contained and provided in a frame (2) of a bicycle (1) so as to be not viewable from outside of the bicycle (1).