John Bernard Ryan (November 12, 1868 – August 21, 1952) was a Major League Baseball catcher. He played from 1889 to 1913 in the American Association, National League and American League. He is one of only 31 players in baseball history to date to have appeared in Major League games in four decades.
Ryan was born in Haverhill, Massachusetts to Irish immigrants. He played baseball from an early age and began playing professionally by age 18.
He was a manager in the minor leagues in 1909–1911, 1922–1923, 1926, and 1928–1929.