John George Alleman (December 3, 1804 – July 14, 1865) was a missionary Catholic priest who served in the states of Ohio, Iowa and Illinois. He served as a priest in the Dominican Order from 1834 to 1840, after which time he was expelled from the order. He then served as a secular priest in the Diocese of Dubuque from 1840 to 1851, and in the Diocese of Chicago from 1851 to 1863. During his hospitalization in St. Louis, Missouri, (1863–1865) he was accepted back into the Dominican Order.