  Electroweak measurements place significant bounds on higher-dimensional
versions of the standard model in which the gauge and Higgs fields have
Kaluza-Klein excitations. These bounds may be altered quantitatively if chiral
matter is also allowed to propagate in the higher-dimensional `bulk'. We
determine the electroweak constraints on a number of models of this type,
including scenarios in which only the leptons or only the first two generations
of matter fields propagate in the bulk. We also consider the possibility that
different factors of the electroweak gauge group may be distinguished by their
bulk/three-brane assignment, and study a minimal extra-dimensional Z' model. We
find typical bounds on the compactification scale between 1.5 and 4 TeV, and
comment on models in which these bounds might be significantly relaxed.
