Abstract: A compact double Cardan motion universal joint has a substantially cylindrical housing having an input end and an output end, with an input shaft and ball joint and an output shaft and interengaging ball joint, respectively; each ball joint consisting of a substantially spherical ball on the shaft member, a ball seat torsionally fixed in the housing, and pivots for providing articulation of the ball shaft about two orthogonal axes. Interengagement between the ball joints is provided by an interconnection ball joint consisting of a hollow socket on a joining end of one of the spherical ball shaft members of said universal joint, and a spherical ball on a joining end of the other spherical ball shaft member, the interconnection ball joint providing universal pivoting and translating motion at a juncture between interengaging portions of the ball shaft members.