Frederick John Osterling (October 4, 1865, Duquesne, Pennsylvania – July 5, 1934, Pittsburgh, Pennsylvania) was an American architect, practicing in Pittsburgh from 1888. Frederick J. Osterling was born to Philip and Bertha Osterling in Dravosburg, Pennsylvania, in 1865. The Osterling family moved to Allegheny City when Frederick was young. Following his schooling in Allegheny City, Osterling began work in the office of Joseph Stillburg, and was published in American Architect and Building News at age 18. Following a period of European travel, he launched his own practice in 1888. During his career he designed many prominent Pittsburgh buildings, such as the Union Trust Building (1915–17). According to Martin Aurand, Architecture Librarian at Carnegie Mellon University in Pittsburgh, Oster