Abstract: This invention relates to a locking electrical connector which is particularly adapted for lanyard release. The connector has a first contact with an annular inner projection. This contact is adapted for expansion to enlarge the diameter of the inner projection when a mating second contact or jack is being inserted or removed from the contact. A locking collar is mounted for movement between a first position over the first contact, preventing the expansion thereof, and a second position in which the collar does not inhibit the expansion of the contact. The locking collar is normally biased to the first position. The second contact or jack has an annular outer groove and is dimensioned to be seated in the first contact with the annular projection of the first contact in the annular groove of the second contact when the contacts are fully mated.