Leo A. Temmey (November 6, 1894 – April 22, 1975) was an American attorney and 15th attorney general of South Dakota between 1939 and 1943.

Temmey graduated from the University of Minnesota School of Law.

[1] On June 27, 1938, Temmey won the Republican nomination on the first ballot, defeating Charles H. McCay of Salem by a margin of 79,510 to 72,718 votes.

[2] Temmey was elected attorney general by defeating incumbent Democrat attorney general Clair Roddewig by a margin of 144,125 to 123,671 votes.

[3] Temmey was re-elected attorney general by defeating Democrat Andrew Foley by a margin of 170,269 to 122,173 votes.