  The present thesis is divided into three parts. In Part I we address a
problem within Higher-Spin Gauge Theory in dimension three: namely, that of
computing the asymptotic symmetry algebra of supersymmetric models, describing
an infinite spectrum of integer and half-integer higher-spin fields. In Part II
we investigate higher-spin theories in dimension four or greater, where we
classify the consistent cross interactions between free gauge fermions of
arbitrary spin and a photon or a graviton. A third part supplements the bulk of
the manuscript with technical appendices.
