Frank Michler Chapman (June 12, 1864 – November 15, 1945) was a US ornithologist.

Chapman was born in West Englewood , New Jersey and attended Englewood Academy. He joined the staff of the American Museum of Natural History in 1888 as assistant to Joel Asaph Allen. In 1901 he was made associate Curator of Mammals and Birds and in 1908 Curator of Birds.

Chapman came up with the original idea for the Christmas Bird Count.