MLB Single Season Home Run Leaders


All Time Records
Single Season Records
MLB Milesontes
Career BA Leaders Highest BA in a Season No Hitters and Perfect Games
Career Hits Leaders Most Hits in a Season 300 Wins Club
Career HR Leaders Most HRs in a Season 3000 Strikeouts Club
Career RBI Leaders Most RBIs in a Season 500 Home Run Club
Career Runs Leaders Most Runs in a Season 3000 Hits Club
Career SB Leaders Most SBs in a Season Triple Crown Winners
Career Wins Leaders Most Saves in a Season  
Career Saves Leaders Most K's in a Season  
Career K Leaders Lowest ERA in a Season  
Career ERA Leaders    

For the sake of not creating a debate, no Asterick's were included. Who is the greatest home run hitter will always be debated, but like it not, Barry Bond's 73 Home Runs in 2001 tops the list of the most home runs in a MLB season. Many thought that when Mark McGwire hit 70 in 1998, it may not get broken (see Todd McFarlen and his over $2 million baseball). 42 times a MLBer has hit over 50 home runs in a single season. The debate of steroids and MLB home run records will go on for years.

Most Home Runs in a Single MLB Season
Rank Player Team
HRs
Year
1Barry Bonds San Francisco Giants
73
2001
2Mark McGwire  St. Louis Cardinals
70
1998
3Sammy Sosa  Chicago Cubs
66
1998
4Mark McGwire  St. Louis Cardinals
65
1999
5Sammy Sosa Chicago Cubs
64
2001
6Sammy Sosa Chicago Cubs
63
1999
7Roger Maris New York Yankees
61
1961
8Babe Ruth New York Yankees
60
1927
9Babe RuthNew York Yankees
59
1921
T10Jimmie Foxx Philadelphia Athletics
58
1932
 Hank Greenberg Detroit Tigers
58
1938
 Ryan Howard Philadelphia Phillies  
58
2006
 Mark McGwire  Oakland Athletics
St. Louis Cardinals
58
1997
T14Luis Gonzalez Arizona Diamondbacks  
57
2001
 Alex Rodriguez  Texas Rangers
57
2002
T16Ken Griffey Seattle Mariners
56
1997
 Ken GriffeySeattle Mariners 
56
1998
 Hack Wilson Chicago Cubs
56
1930
T19 Jose Bautista Toronto Blue Jays
54
2010
 Ralph Kiner Pittsburgh Pirates
54
1949
 Mickey Mantle New York Yankees
54
1961
 David Ortiz Boston Red Sox
54
2006
 Alex Rodriguez  New York Yankees
54
2007
 Babe RuthNew York Yankees
54
1920
 Babe RuthNew York Yankees
54
1928
T26George Foster  Cincinnati Reds
52
1977
 Mickey MantleNew York Yankees
52
1956
 Willie Mays San Francisco Giants
52
1965
 Mark McGwire  Oakland Athletics
52
1996
 Alex Rodriguez  Texas Rangers
52
2001
 Jim Thome Cleveland Indians
52
2002
T32Cecil Fielder  Detroit Tigers
51
1990
 Andruw Jones  Atlanta Braves
51
2005
 Ralph Kiner Pittsburgh Pirates
51
1947
 Willie Mays New York Giants
51
1955
 Johnny Mize New York Giants
51
1947
T37Brady Anderson Baltimore Orioles
50
1996
 Albert Belle  Baltimore Orioles
50
1995
 Prince Fielder Milwaukee Brewers
50
2007
 Jimmie Foxx Boston Red Sox
50
1938
 Sammy Sosa  Chicago Cubs
50
2000
 Greg Vaughn  San Diego Padres
50
1998

Updated: Mar. 25th 2011

Sources:
baseball-reference.com
baseball-almanac.com
wikipedia.org
thebaseballcube.com