An electrical connector including: a housing including an outer peripheral part; and a lock arm provided with the outer peripheral part. The lock arm is swingable like a seesaw and detachably engages with a locking part provided with another housing of a mating connector. The lock arm extends along a coupling direction toward the mating connector. A pair of side wall parts are provided with the outer peripheral part such that the pair of side wall parts oppose to each other from both sides of the lock arm. An elastic support mechanism for swingably supporting the lock arm is provided between a lower face part of the lock arm and inner side faces of the pair of side wall parts.