Leo Maria Joseph Dielmann (August 14, 1881 - December 21, 1969) was a prominent and prolific architect in Texas. He designed over 100 churches, with several of them, along with other buildings, now listed on the U.S. National Register of Historic Places. In 1926, Deilmann completed Our Lady of Guadalupe Catholic Church on San Antonio's West Side to serve its Mexican-American population. The red brick building is Romanesque, with strong elements of the Lombardy style. Notable works include: