As of 2015, Manchester United has the largest fan base of all football clubs. The club has approximately 354 million global fans, according to a 2011 study by German company SPORT+MARKT.
The same report indicated that Barcelona is the second-largest, boasting roughly 270 million fans worldwide. The next largest English clubs are Chelsea and Liverpool, with 135 million and 113 million followers, respectively.
Attendance figures through the first half of the 2014-2015 season indicate an average of 75,000 spectators per Manchester United home match, which is at least 15,000 more than the second-highest club, Arsenal.
A 2012 report by Forbes magazine also ranked Manchester United as the sport's most valuable.