Ferrule, optical connector, and method for manufacturing optical connector

To provide: a ferrule that is compatible with high-speed large-capacity communication and that is less prone to damage even if repeatedly subjected to stress; an optical connector; and a method for manufacturing an optical connector. A ferrule 10 for connecting a plurality of optical fibers comprises: a fiber hole 100 which is provided in a connection end surface 11a and into which an optical fiber is inserted; a boot insertion hole 300 which is provided in a rear end surface 11b and into which a boot 60, through which a plurality of optical fibers can be inserted, is inserted; an internal space 400 for establishing communication between a plurality of fiber holes 100 and the boot insertion hole 300; and a flange section 600 which is provided on the side of the rear end surface 11b and protrudes from a surface adjacent to the rear end surface 11b. The depth T of the boot insertion hole 300 is shorter than the connection-direction length L of the flange section 600.