Loyal Johnston Martin (February 16, 1863 – April 22, 1950) was an American lawyer and politician who served as the 11th Mayor of Tulsa from 1910 to 1912 and in the South Dakota Senate from 1901 to 1902.

The family moved to Oneida, Illinois when he was aged 3.

He attended Knox College in Illinois and University of Michigan Law School.

He began his law career in 1889 in Miner County, South Dakota.

[1] He served in the South Dakota Senate between 1901 and 1902 representing Miner County as a member of the Populist Party.