  We study N=1,2,4 higher spin superalgebras in four dimensions and higher spin
gauge theories based on them. We extend the existing minimal N=2,4 theories and
find a minimal N=1 theory. Utilizing the basic structure of the minimal N=8
theory, we express the full field equations for the N=1,2,4 theories in a
universal form without introducing Kleinian operators. We also use a
non-minimal N=4 higher spin algebra tensored with U(3) to describe a higher
spin extension of N=4 supergravity coupled to the massless vector multiplets
arising in the KK spectrum of 11D supergravity on the N=3 supersymmetric AdS_4
x N^{010} background. The higher spin theory also contains a triplet of vector
multiplets which may play a role in the super-Higgs effect in which N=4 is
broken down to N=3.
