Antoni Julian Nowowiejski (11 February 1858 - 28 May 1941) was a Polish bishop of Płock (1908-1941), titular archbishop of Silyum, first secretary of Polish Episcopal Conference (1918-1919), honorary citizen of Płock and historian. He died at the hands of the Germans in Soldau concentration camp near Działdowo on 28 May 1941, and was subsequently beatified by Pope John Paul II in 1999 as one of the 108 Martyrs of World War Two.