Louis Marcus (1880-1936) was a Salt Lake City mayor and businessman in the motion picture industry.

Louis Marcus was born on January 9, 1880 in Brooklyn, New York to Eleazor Albert and Diana Gumpel Marcus. He moved to Salt Lake City, Utah in 1907, where he married Gertrude Levin on January 16, 1912. Together they had one child, Louis Howard Marcus in 1919.

In Salt Lake City, Marcus became involveed in the motion picture business as an operator, exchange manager, and owner of film exchange and theatres. He established a theatre chain in Utah, as well as other mountain states. The companies he was involved in include Louis Marcus Enterprises, Publix-Marcus, Inc., Gem State Theatres, Victory Amusement Company, Notable Feature Films Company and others. In 1927 he purchased the Orpheum Theatre, to which he increased the seating capacity, added a Wurlitzer organ, changed its name to Capitol Theatre Building, and in 1929 showed the first talking picture in Salt Lake City.

Marcus's business ventures extended into real estate and was the president of the United Realty Co., and served as the director of Tracy Loan & Trust Co., as well as Walker Bank & Trust Co. He was also very active in his community and civic service. He was a member of the Salt Lake City Chamber of Commerce, was a York and Scottish Rite Mason, and member of the B'nai B'rith.

In 1931 he ran for and was elected as mayor of Salt Lake City, and served from 1932-1935. He was the first Jew to be elected to this position. Louis was also a member of several clubs, including Alta, Rotary, Ft. Douglas, and the Country clubs in both Salt Lake City and Ogden, UT.

Marcus died on July 27, 1936 in Salt Lake City, UT.