Measuring the size of a football club's fanbase involves analyzing global television viewership data, official social media follower counts, international merchandise sales, and stadium attendance figures. Manchester United consistently ranks as the English club with the largest overall global fanbase, boasting hundreds of millions of supporters worldwide spanning continents from Asia and Africa to the Americas. Other massive English clubs like Liverpool, Arsenal, and Chelsea also command immense international followings, but Manchester United's decades of sustained global marketing and historical success during the Premier League era have cemented their status as the most widely supported English football institution across the globe.