We study the single production of top and fourth standard model family
quark t' in ep and gamma p collisions. The subprocesses eb --> t(t')u
psilon(e) and gamma b --> t(t')W for the production of t and t' are co
nsidered. We find the total cross-section for single top production as
similar to 38 pb and similar to 27 ph at future ep and gamma p collid
ers with root S-ep = 5.5 TeV, respectively.