The increased polarization in the United States among the political branches and citizenry affects the selection, work, perception, and relative power of state and federal judges, including justices of the US Supreme Court. Polarization in the United States over the last few decades matters to the American judicial system in at least four ways. First, polarization affects judicial selection, whether the selection method is (sometimes partisan-based) elections or appointment by political actors. In times of greater polarization, governors and presidents who nominate judges, legislators who confirm judges, and voters who vote on judicial candidates are more apt to support or oppose judges on the basis of partisan affiliation or cues. Second, driven in part by selection mechanisms, polarization may be reflected in the decisions that judges make, especially on issues that divide people politically, such as abortion, guns, or affirmative action. The Supreme Court, for example, often divides along party and ideological lines in the most prominent and highly contested cases. Those ideological lines now overlap with party as we enter a period in which all the Court liberals have been appointed by Democratic presidents and all the Court conservatives have been appointed by Republican presidents. Third, increasingly polarized judicial decisions appear to be causing the public to view judges and judicial decision making (at least on the US Supreme Court) through a more partisan lens. Fourth, polarization may affect the separation of powers, by empowering courts against polarized legislative bodies sometimes paralyzed by gridlock. The review concludes by considering how increased polarization may interact with the judiciary and judicial branch going forward and by suggesting areas for future research.