<Tr> <Td> Frank Robinson </Td> <Td> 12 </Td> <Td> 1956--65 (Cincinnati Reds), 1966--71 (Baltimore Orioles), 1972 (Los Angeles Dodgers), 1973--74 (California Angels), 1974--76 (Cleveland Indians) </Td> </Tr> <Tr> <Td> Babe Ruth </Td> <Td> 12 </Td> <Td> 1914--19 (Boston Red Sox), 1920--34 (New York Yankees), 1935 (Boston Braves) </Td> </Tr> <Table> <Tr> <Th> HR </Th> <Th> Team </Th> <Th> Season </Th> </Tr> <Tr> <Td> 264 </Td> <Td> Seattle Mariners </Td> <Td> </Td> </Tr> <Tr> <Td> 260 </Td> <Td> Texas Rangers </Td> <Td> 2005 </Td> </Tr> <Tr> <Td> 257 </Td> <Td> Baltimore Orioles </Td> <Td> </Td> </Tr> <Tr> <Td> 257 </Td> <Td> Toronto Blue Jays </Td> <Td> </Td> </Tr> <Tr> <Td> 253 </Td> <Td> Baltimore Orioles </Td> <Td> 2016 </Td> </Tr> <Tr> <Td> 249 </Td> <Td> Houston Astros </Td> <Td> 2000 </Td> </Tr> <Tr> <Td> 246 </Td> <Td> Texas Rangers </Td> <Td> </Td> </Tr> <Tr> <Td> 245 </Td> <Td> Seattle Mariners </Td> <Td> </Td> </Tr> <Tr> <Td> 245 </Td> <Td> New York Yankees </Td> <Td> 2012 </Td> </Tr> <Tr> <Td> 244 </Td> <Td> Seattle Mariners </Td> <Td> 1999 </Td> </Tr> <Tr> <Td> 244 </Td> <Td> Toronto Blue Jays </Td> <Td> 2000 </Td> </Tr> <Tr> <Td> 244 </Td> <Td> New York Yankees </Td> <Td> 2009 </Td> </Tr> <Tr> <Td> 243 </Td> <Td> Oakland Athletics </Td> <Td> </Td> </Tr> <Tr> <Td> 242 </Td> <Td> Chicago White Sox </Td> <Td> </Td> </Tr> <Tr> <Td> 242 </Td> <Td> New York Yankees </Td> <Td> </Td> </Tr> <Tr> <Td> 241 </Td> <Td> New York Yankees </Td> <Td> 2017 </Td> </Tr> <Tr> <Td> 240 </Td> <Td> New York Yankees </Td> <Td> 1961 </Td> </Tr> </Table> <Tr> <Th> HR </Th> <Th> Team </Th> <Th> Season </Th> </Tr>

Most home runs in a season mlb team