The relativistic ponderomotive Hamiltonian is derived under as general conditions as possible. Arbitraryk&rgr;,E∥/E⊥, &ohgr;/&OHgr;,v/c<1, wave polarization, spatial modulation of the wave, and nonuniformities in the background electric and magnetic fields are introduced in a systematic way. This calculation is a modification of guiding center theory, because in addition to averaging over gyration, there is also an averaging over rapid oscillations of the wave. Therefore, as a by‐product of our objective, a new formulation of the relativistic guiding center motion is derived.