Julius F. Harder was an American architect of New York.
He designed the Palmetto Building, a skyscraper built during 1912-1913 that was then the tallest building in the state of South Carolina. The building's construction was supervised by local architects Wilson & Sompayrac.
He designed the award-winning Samuel Hahnemann Monument, Reservation 64, Massachusetts & Rhode Island Aves. at Scott Cir. NW Washington, DC (Harder, Julius F.), NRHP-listed
He served as treasurer of the Architectural League of America at its fifth annual convention.