A releasable locking connector assembly includes a coupling nut rotatably coupled to a connector body; splines on the connector body or the coupling nut; and a lock ring having mating splines that is translatable with respect to the connector body and the coupling nut between engaged and disengaged positions. The mating splines engage the splines when the lock ring is in the engaged position to prevent rotation of the coupling nut, and the mating splines are spaced from the splines when the lock ring is in the disengaged position to permit rotation of the coupling nut. A moveable index ring is movable between a locked position, in which the lock ring is in the engaged position, and an unlocked position, in which the lock ring is in the disengaged position. A push ring sequentially moves the moveable index ring between the locked and unlocked positions.