Benjamin Milton Willoughby (April 8, 1855 – June 29, 1940) was an American lawyer, politician, and judge.
In 1878, he began studying law at Cincinnati College, graduating in 1879 and being admitted to the bar the same year.
Willoughby became a judge for Indiana's 12th Circuit Court in 1912, a position he held until 1918.
Willoughby also served as President of the Vincennes Northern & Southern Traction Company, incorporated in 1911, which constructed railroad tracks that connected Vincennes to the rest of Knox County and Sullivan County.
Willoughby emerged as a leading critic of Prohibition and became a personal enemy of the Rev.
In 1930, Willoughby was defeated in his bid for re-election following a challenge for the Republican nomination by Thomas B. Coulter, judge of the Knox County Circuit Court.
Shumaker, Anti-Saloon League, and the KKK threw their support behind Coulter, leading him to barely prevail over Willoughby in an extremely close contest, though Coulter was later defeated in the general election by Willoughby's eventual successor, Democrat Walter E.