We investigate the polarization properties of Comptonized X-rays from relativistic jets in Active Galactic Nuclei ( AGN ) using Monte Carlo simulations . We consider three scenarios commonly proposed for the observed X-ray emission in AGN : Compton scattering of blackbody photons emitted from an accretion disk ; scattering of cosmic microwave background ( CMB ) photons ; and self-Comptonization of intrinsically polarized synchrotron photons emitted by jet electrons . Our simulations show that for Comptonization of disk and CMB photons , the degree of polarization of the scattered photons increases with the viewing inclination angle with respect to the jet axis . In both cases the maximum linear polarization is \approx 20 \% . In the case of synchrotron self-Comptonization ( SSC ) , we find that the resulting X-ray polarization depends strongly on the seed synchrotron photon injection site , with typical fractional polarizations P \approx 10 - 20 \% when synchrotron emission is localized near the jet base , while P \approx 20 - 70 \% for the case of uniform emission throughout the jet . These results indicate that X-ray polarimetry may be capable of providing unique clues to identify the location of particle acceleration sites in relativistic jets . In particular , if synchrotron photons are emitted quasi-uniformly throughout a jet , then the observed degree of X-ray polarization may be sufficiently different for each of the competing X-ray emission mechanisms ( synchrotron , SSC or external Comptonization ) to determine which is the dominant process . However , X-ray polarimetry alone is unlikely to be able to distinguish between disk and CMB Comptonization .