| 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 |