James Edward "Tip" O'Neill (May 15, 1860 – December 31, 1915) was a Canadian professional baseball player from approximately 1875 to 1892. He began playing organized baseball in Woodstock, Ontario, and later played ten seasons in Major League Baseball, principally as a left fielder, but also as a pitcher, for four major league clubs.

While playing with the St. Louis Browns (later renamed The St. Louis Cardinals) from 1884 to 1889, O'Neill helped the club compile a 516–247 record while also winning four pennants and the 1886 World Series. O'Neill won two American Association batting championships during those years and became the second person in major league history to hit for a triple crown, leading the league in 1887 with a .435 batting average, 14 home runs and 123 runs batted in (RBIs). He also rewrote the major league record book, establishing new records in at least eight categories, including the highest batting average (originally .492, adjusted to .435), on-base percentage (.490) and slugging percentage (.691), and the most hits (225), runs scored (167), doubles (52), extra base hits (84), and total bases (357) in a single season. His adjusted .435 batting average in 1887 remains the second highest in major league history.

O'Neill, dubbed "Canada's Babe Ruth", was posthumously inducted into both the Canadian Baseball Hall of Fame and the Ontario Sports Hall of Fame. Each year since 1984, the Canadian Baseball Hall of Fame has presented the Tip O'Neill Award to the best Canadian baseball player.

O'Neill was born in 1860 at Springfield, Canada West, a village in modern-day Southwestern Ontario that was later incorporated into the city of Malahide. While O'Neill was a boy, his family moved approximately 30 miles northeast to Woodstock, where his parents operated a hotel.

In 1875, O'Neill began playing organized baseball in Woodstock, and became known as "The Woodstock Wonder." He also traveled with barnstorming teams. In 1881, he reportedly played in Detroit, and in 1882, he played for the New York Metropolitans in the League Alliance.

O'Neill made his major league debut on May 5, 1883, as a pitcher for New York Gothams (later renamed the Giants) of the National League. Shortly after his major league debut, Sporting Life wrote: "O'Neill, the New York change pitcher, seems to have but one element of effectiveness in his delivery, viz.: fast and slow. This is a very weak reliance nowadays, as batsmen have only to note the speed of the ball and wait for a good one. O'Neill's delivery is wild and erratic -- hard work for the catcher and busy work for the field." O'Neill appeared in 19 games as a starting pitcher for the Gothams and compiled a win–loss record of 5–12 and a 4.07 earned run average (ERA).

In 1884, O'Neill joined Charlie Comiskey's St. Louis Browns (later renamed the Cardinals) of the American Association. He was signed by Comiskey to replace pitcher Tony Mullane, who left the Browns after the 1883 season. O'Neill compiled an 11–4 win–loss record with a 2.68 ERA and led the league with a .733 winning percentage as pitcher. However, his arm reportedly "went back on him" during the 1884 season, requiring him to switch from pitching to playing in the outfield. He ended up playing 64 games as an outfielder in 1884 and was exclusively an outfielder thereafter.

In 1885, O'Neill missed much of the season, suffering an injury on June 10 and not returning to the lineup until September 3. Despite the injury, O'Neill established himself as the Browns' best batter, hitting .350 in 52 games, nearly 80 points higher than any other player on the team. The 1885 Browns won the American Association pennant with a 79-33 record and tied the Chicago White Stockings in the 1885 World Series. O'Neill scored four runs but hit .208 in his first World Series.