New York Yankees, New York Giants (Now San Fransisco Giants), Philadelphia Athletics (Now Oakland Athletics), Philadelphia Phillies, Boston Red Sox, Cincinnati Reds, and the Toronto Blue Jays have all won back to back World Series during their existence. That's 7 clubs total.
Source: http://en.wikipedia.org/wiki/List_of_World_Series_champions
Chat with our AI personalities
The college teams that have won back to back national championships in Baseball are:
1.) Texas 1949-1950
2.) USC 1970-1974
3.) Stanford 1987-1988
4.) LSU 1996-1997
5.) Oregon State 2006-2007
6.) South Carolina 2010-2011