<P> The single season record is 73, set by Barry Bonds in 2001 . Other notable single season records were achieved by Babe Ruth who hit 60 in 1927, Roger Maris, with 61 home runs in 1961, and Mark McGwire, who hit 70 in 1998 . </P> <P> Negro League slugger Josh Gibson's Baseball Hall of Fame plaque says he hit "almost 800" home runs in his career . The Guinness Book of World Records lists Gibson's lifetime home run total at 800 . Ken Burns' award - winning series, Baseball, states that his actual total may have been as high as 950 . Gibson's true total is not known, in part due to inconsistent record keeping in the Negro Leagues . The 1993 edition of the MacMillan Baseball Encyclopedia attempted to compile a set of Negro League records, and subsequent work has expanded on that effort . Those records demonstrate that Gibson and Ruth were of comparable power . The 1993 book had Gibson hitting 146 home runs in the 501 "official" Negro League games they were able to account for in his 17 - year career, about 1 homer every 3.4 games . Babe Ruth, in 22 seasons (several of them in the dead - ball era), hit 714 in 2503 games, or 1 homer every 3.5 games . The large gap in the numbers for Gibson reflect the fact that Negro League clubs played relatively far fewer league games and many more "barnstorming" or exhibition games during the course of a season, than did the major league clubs of that era . </P> <P> Other legendary home run hitters include Jimmie Foxx, Mel Ott, Ted Williams, Mickey Mantle (who on September 10, 1960, mythically hit "the longest home run ever" at an estimated distance of 643 feet (196 m), although this was measured after the ball stopped rolling), Reggie Jackson, Harmon Killebrew, Ernie Banks, Mike Schmidt, Dave Kingman, Sammy Sosa (who hit 60 or more home runs in a season 3 times), Ken Griffey, Jr. and Eddie Mathews . In 1987, Joey Meyer of the Denver Zephyrs hit the longest verifiable home run in professional baseball history . The home run was measured at a distance of 582 feet (177 m) and was hit inside Denver's Mile High Stadium . Major League Baseball's longest verifiable home run distance is about 575 feet (175 m), by Babe Ruth, to straightaway center field at Tiger Stadium (then called Navin Field and before the double - deck), which landed nearly across the intersection of Trumbull and Cherry . </P> <P> The location of where Hank Aaron's record 755th home run landed has been monumented in Milwaukee . The spot sits outside Miller Park, where the Milwaukee Brewers currently play . Similarly, the point where Aaron's 715th homer landed, upon breaking Ruth's career record in 1974, is marked in the Turner Field parking lot . A red - painted seat in Fenway Park marks the landing place of the 502 - ft home run Ted Williams hit in 1946, the longest measured homer in Fenway's history; a red stadium seat mounted on the wall of the Mall of America in Bloomington, Minnesota, marks the landing spot of Harmon Killebrew's record 520 - foot shot in old Metropolitan Stadium . </P>

What is the longest home run hit in major league baseball