  We study the possible contributions of dimension six operators containing
fermion fields to Higgs production at a 500 GeV or 1 TeV $e^+e^-$ linear
collider. We show that -- depending on the production mechanism -- the effects
of such operators can be kinematically enhanced relative to Standard Model (SM)
contributions. We determine constraints on the operator coefficients implied by
existing precision electroweak measurements and the scale of neutrino mass. We
find that even in the presence of such constraints, substantial deviations from
SM Higgs production cross-sections are possible. We compare the effects of
fermionic operators with those associated with purely bosonic operators that
have been previously discussed in the literature.
