The 1916 United States Senate election in Maine was held on September 11, 1916.
Incumbent Democratic Senator Charles F. Johnson ran for re-election to a second term in office, but was defeated by Republican Frederick Hale, the son of Johnson's predecessor Eugene Hale.
Senator Johnson was unopposed in the Democratic primary.
Three days before the primary, Maine's other U.S. Senator Edwin C. Burleigh died. After losing this primary, Fernald ran to complete Burleigh's unexpired term and won.
Hersey ran for and won the election to Maine's 4th congressional district, which was vacated by Frank E. Guernsey, who also ran in the special election for Senate.