An optical fiber connector includes a connector housing and a positioning unit. The connector housing has two opposite side walls, a base wall disposed between and interconnecting the side walls, and a lid disposed between and inter-engaging releasably the side walls. The connector housing defines an inner space, and an access opening in spatial communication with the inner space and covered by the lid. The positioning unit is mounted in the inner space and includes first and second holding members and a coupling sleeve extending into and interconnecting the first and second holding members. The positioning unit is inserted into the inner space through the access opening so as to be mounted in the inner space before covering the access opening with the lid.