One Man's Hero is a 1999 historical war drama film directed and produced by Lance Hool and starring Tom Berenger, Joaquim de Almeida, Daniela Romo, and Patrick Bergin. It dramatizes the true story of John Riley and the Saint Patrick's Battalion, a group of Irish Catholic immigrants who desert the mostly Protestant U.S. Army to join the Catholic Mexican army during the Mexican–American War of 1846 to 1848.