Checkmate, a division of Task Force X, is a fictional covert operations agency appearing in American comic books published by DC Comics. It first appeared in Action Comics #598 and proceeded to have its own ongoing title in Checkmate!. In the wake of events depicted in the mini-series The OMAC Project and Infinite Crisis, Checkmate had been re-chartered as a United Nations Security Council-affiliated agency and had its own series, Checkmate (vol. 2).