Judson Harmon (February 3, 1846 - February 22, 1927) was a Democratic politician from Ohio. He served as United States Attorney General under President Grover Cleveland and later served as the 45th Governor of Ohio.

Harmon was born in Newtown, Ohio. Harmon graduated from Denison University in 1866 He graduated from the Law School of Cincinnati College and was admitted to the bar in 1869. Harmon was elected judge of the Common Pleas Court in 1876, but left months later to run unsuccessfully for the State Senate. He was elected judge of the Superior Court of Cincinnati in 1878 and served until he resigned in 1887 to resume the practice of law. He was appointed Attorney General by President Cleveland on June 8, 1895 upon the elevation of Richard Olney to become United States Secretary of State, serving out the remainder of Cleveland's term. Harmon was elected Governor of Ohio in 1908, and two two-year terms from 1909-1913 - defeating eventual president Warren G. Harding for re-election in 1910 - before retiring.

Harmon County, Oklahoma is named for him.

|- style="text-align: center;" | width="30%" |Preceded by:
Andrew L. Harris | width="40%" style="text-align: center;" |Governor of Ohio
1909–1913 | width="30%" |Succeeded by:
James M. Cox