| Batter Team Age Year HR Reign Record breaker | |
| George Hall Philadelphia Athletics 27 1876 5 3 years — | |
| Charley Jones Boston Red Caps 29 1879 9 4 years 6th on July 31 off George Bradley | |
| Harry Stovey Philadelphia Athletics 27 1883 14 1 year 10th on August 1 off Jack Neagle | |
| Ned Williamson Chicago White Stockings 27 1884 27 35 years 15th on July 9 off Ed Bagley | |
| Babe Ruth Boston Red Sox 24 1919 29 1 year 28th on September 24 off Bob Shawkey | |
| Babe Ruth New York Yankees 25 1920 54 1 year 30th on July 19 off Dickie Kerr | |
| Babe Ruth New York Yankees 26 1921 59 6 years 55th on September 15 off Bill Bayne | |
| Babe Ruth New York Yankees 32 1927 60 34 years 60th on September 30 off Tom Zachary | |
| Roger Maris New York Yankees 27 1961 61 37 years 61st on October 1 off Tracy Stallard | |
| Mark McGwire St. Louis Cardinals 35 1998 70 3 years 62nd on September 8 off Steve Trachsel | |
| Barry Bonds San Francisco Giants 36 2001 73 17 years 71st on October 5 off Chan Ho Park | |