Mercer is the given name of:
People Mercer Cook (1903–1987), African-American diplomat and professor Mercer Ellington (1919–1996), American jazz trumpeter, composer and arranger Mercer Mayer (born 1943), American children's book writer and illustrator Mercer Reynolds (born 1945), American businessman Mercer Simpson (1926–2007), English writer active in Welsh literary circles
Fictional characters Mercer (G.I. Joe), in the G.I. Joe universe