The record for the most home runs hit by a pitcher in a single season is 9, achieved by Wes Ferrell in 1931.
He holds the world record for the most home runs in a single season.
roger maris
Barry Bond
Barry Bonds
73 HR- the record was set in 2001.
Barry Bonds is the current holder, with 73 home runs in 2001.
In 1998, St. Louis Cardinals slugger Mark McGwire hit 70 home runs to break Roger Maris' single season record.
In 1927 Babe Ruth hit 60 home runs to break his own single season home record of 59 set in 1921.
Coors field
Sammy Sosa hit 66 home runs in the year 1998, which set a Chicago Cubs single-season record.
Barry Bonds* Holds both records. He broke Hank Aaron's record of homers in 2007 and has 762 and broke McGwire's single-season record in 2001 and has 73. But note the asterisk.
i believe the record is 303 in 1999 at coors field