The Major League Baseball (MLB) record for most grand slam home runs hit in a game is 2 by 13 players, most recently Josh Willingham (USA) playing for the Washington Nationals (USA) against the Milwaukee Brewers (USA) on 27 July 2009.
The Major League Baseball (MLB) record for most grand slam home runs hit in a game is 2 by 13 players, most recently Josh Willingham (USA) playing for the Washington Nationals (USA) against the Milwaukee Brewers (USA) on 27 July 2009.