Jeremiah O'Rourke, FAIA, (1833 – 1915), was an Irish-American architect known primarily for his designs of Roman Catholic churches and institutions and Federal post offices. He was a founder of the Newark-based architectural firms of Jeremiah O'Rourke (active from the 1850s to the 1880s) and Jeremiah O'Rourke & Sons (active from the 1880s until his death).