John "Jocko" Milligan (August 8, 1861 – August 29, 1923) was an American professional baseball player who played catcher in Major League Baseball from 1884 to 1893.

[1] Milligan played for the Philadelphia Athletics, St. Louis Browns, Philadelphia Athletics, Washington Senators, Baltimore Orioles, and New York Giants.

[2] In 772 games over ten seasons, Milligan posted a .286 batting average (848-for-2964) with 440 runs, 189 doubles, fifty triples, forty-nine home runs, 497 runs batted in, 210 bases on balls, .341 on-base percentage, and .433 slugging percentage.

Milligan died on August 29, 1923, in Philadelphia, Pennsylvania and was interred at the Mount Moriah Cemetery.