B-hCD200/hCD200R mice express human CD200 and CD200R. B-hCD200 MC38 cells express human CD200. Tumor growth of B-hCD200 MC38 and wild-type MC38 cells was comparable in B-hCD200/hCD200R mice. Combined anti-human CD200 and anti-mouse PD-1 antibodies effectively inhibited B-hCD200 MC38 tumor growth in B-hCD200/hCD200R mice. B-hCD200/hCD200R mice paired with B-hCD200 MC38 cells provide a model to evaluate the in vivo efficacy of anti-human CD200 antibodies and immune checkpoint therapies.