The thermal relaxation of a two‐dimensional (2‐D) plasma in a uniform magnetic field is investigated. Previous workers [J. Plasma Phys.12, 21 (1974)] observed that the relaxation process is anomalous in that the relaxation may occur more rapidly with a modest magnetic field than without. A simple model is presented which explains the anomalous behavior in terms of correlations between successive collisions. The model predicts the relaxation time to scale as (&ohgr;c/&ohgr;p)−1/2(n&lgr;2D)1/2&ohgr;−1pfor modest magnetic fields (&ohgr;c/&ohgr;p<1). This scaling law is tested with 2‐D electrostatic particle simulations. These simulations show the relaxation time to scale with (&ohgr;c/&ohgr;p)−1/2as predicted by the correlated collision model. For very large magnetic fields (&ohgr;c≫&ohgr;p) the simulations show the relaxation time to increase with &ohgr;cbecause of finite size particle effects as the cyclotron radius becomes comparable to the particle size. The predicted (n&lgr;2D)1/2dependence of the relaxation time was observed at early times in the simulations; however, as the distribution approached a Maxwellian, the dependence shifted toward (n&lgr;2D)1as in an unmagnetized plasma.