Clarence Hobart was a tennis player from the United States. He was a six-time champion at the U.S. National Championships, winning three titles in men's doubles in 1890, 1893 and 1894 and three others in mixed doubles in 1892, 1893 and 1905. Hobart also reached the Challenge Round in the Gentlemen's Singles in 1891, finishing runner-up.

The Hamburg Open is an annual tennis tournament for professional players held in Hamburg, Germany and part of the Association of Tennis Professionals (ATP) Tour.