Born in San Francisco, California in the Bayview neighborhood, O'Doul began his professional career as a left-handed pitcher with the minor-league San Francisco Seals of the Triple-A Pacific Coast League. He had some major-league success with the New York Yankees and Boston Red Sox from to as a reliever. He pitched in one notable game on July 7, 1923, that would go down in the record books. Relieving for starter Curt Fullerton, O'Doul gave up 16 runs over 3 innings of relief, with 14 of those runs coming in the 6th inning alone. Although errors committed by Red Sox fielders meant that only 3 of the 16 runs were earned, O'Doul set the major league record for most runs allowed by a reliever in one appearance, a record later equaled by St. Louis Cardinals pitcher Johnny Stuart in 1925 and Philadelphia Phillies pitcher Dutch Schesler in 1931 (although both needed 8 innings to allow 16 runs). Following the season, O'Doul developed a sore arm, which forced him to give up pitching.