  The electroweak Higgs doublets are identified as components of a vector
multiplet in a higher dimensional supersymmetric field theory. We construct a
minimal model in 6D where the electroweak $SU(2) \otimes U(1)$ gauge group is
extended to SU(3), and unified 6D models with the unified SU(5) gauge symmetry
extended to SU(6). In these realistic theories the extended gauge group is
broken by orbifold boundary conditions, leaving Higgs doublet zero modes which
have Yukawa couplings to quarks and leptons on the orbifold fixed points. In
one SU(6) model the weak mixing angle receives power law corrections, while in
another the fixed point structure forbids such corrections. A 5D model is also
constructed in which the Higgs doublet contains the fifth component of the
gauge field. In this case Yukawa couplings are introduced as non-local
operators involving the Wilson line of this gauge field.
