A terminal insertion apparatus having a wire holding unit holding two wires, each wire having a terminal, a connector holding unit holding a connector housing having at least two holes for receiving terminals, and a terminal insertion head is disclosed. The terminal insertion head has a wire gripping unit having a first holder and a second holder. The first holder and second holder are movable in a vertical direction toward and away from the wire holding unit and are movable in a horizontal direction toward and away from the connector holding unit. The first holder has an outer grip and an inner grip that together hold one of the two wires while the second holder has an outer grip and an inner grip that together hold the remaining of the two wires.