John F. Main (1864 – October 13, 1942)[1][2] was a justice of the Washington Supreme Court from 1912 to 1942.

Born in Seaton, Mercer County, Illinois, Main was raised on a farm there,[3] and attended Monmouth College.

[6] Main was unsuccessful, but in 1909, Governor Marion E. Hay appointed Main to a seat on the King County Superior Court vacated by the elevation of George E. Morris to the state supreme court.

[2] He planned to seek a fifth term in 1942, winning the Republican primary for the seat, but thereafter was forced to withdraw from the election due to failing health, leaving Joseph A. Mallery running unopposed.

[1][4] Main died at a sanitarium in Seattle at the age of 78, following a period of failing health.