An optical connector (1) includes an housing (2) having a front wall, an upper wall, a bottom wall, a pair of side walls and a receiving cavity (215) formed therebetween for receiving a mating plug; and an optical member (3) having an optical portion (31) for receiving or emitting light and a number of contacts connected to the optical portion; an insulative cover member (25) attached to the housing and defining a first portion (251) covering an upper portion of the housing and a second portion (258) enclosing a rear portion of the housing, the first portion defining a cutout (252) extending therethrough along an up-to-down direction; a metal lock member (6) defining a lateral arm (61) being retained in the cutout and a locking portion (62) extending downward from the lateral arm and projecting through the housing to be soldered to a printed circuit board, the locking portion locks with the housing.