Henry Siddons Mowbray: (August 5, 1858 - 1928) was an American artist.

He was born of English parents at Alexandria, Egypt. Left an orphan, he was taken to America by an uncle, who settled at North Adams, Massachusetts. After a year at the United States Military Academy at West Point, he went to Paris and entered the atelier of Leon Bonnat, his first picture, Aladdin, bringing him to public notice. He was made a full member of the National Academy of Design in 1891.

Subsequently he was best known for his decorative work, especially The Transmission of the Law, Appellate Court House; ceiling for the residence of F. W. Vanderbilt; and the ceiling and walls of the library of the University Cluball in New York City. This last was executed in Rome, where, in 1903, he was made director of the American Academy.