Eighteen different players have been full-time captains of the Boston Red Sox, an American professional baseball franchise also known previously as the Boston Americans. The list was created from scratch by baseball historian Howard W. Rosenberg in 2004. The Red Sox front office contacted Rosenberg in advance of Jason Varitek being named captain that year, after learning that Rosenberg, author of a 2003 book featuring captains in 19th-century baseball, had disputed the official count of captains in New York Yankees franchise history.