Here is a link to a website that has the history of "which" number were worn for the Red Sox as early as 1931.
Click on the link to your right for the Boston Red Sox stats including uniform numbers.
Currently Dustin Pedroia is number 15 for the Red Sox.
Jacoby Ellsbury wears 46 for the Red Sox now.
Among those who have are: Luis Tiant, Tom Brewer & manager Dick Williams
No one muahahahhahaha
Nomar Garciaparra, Rocco Baldelli before that not sure
Daisuke Matsuzaka currently wears # 18 for the Red Sox, Jason Kendall the catcher for the Brewers also wears the number.