Oscar Goodbar Johnston (January 27, 1880 - October 3, 1955) was an American politician and public officer from the state of Mississippi.

[1][2] In the 1908 and 1910 sessions, he served on the Judiciary, Federal Relations, Corporations, and Mississippi Levees committees.

[1] In the 1916 session, he attempted to run for Speaker of the Mississippi House of Representatives, but lost in a three-way race to Martin Sennett Conner.

[6] He left the Legislature to serve in the Tank Corps as a private in World War I, and was commissioned a lieutenant in 1919.

[4] In 1933, he was appointed the Director of Finance for the newly created Agricultural Adjustment Administration (AAA).