William Sierra

William Matthew Sierra, widely recognized as Bill Alfonso, is a former American professional wrestling referee and manager who made a significant impact in the realm of wrestling, particularly during the mid-to-late 1990s with Extreme Championship Wrestling (ECW). Known for his distinctive whistle, which he frequently blew during matches, Alfonso debuted in ECW in May 1995 as a "trouble-shooting referee" introduced by Shane Douglas. His strict adherence to rules often irked fans, especially when he disqualified wrestlers for traditional ECW tactics like using steel chairs, leading to a notable feud with ECW founder Tod Gordon.

Following the closure of ECW, Alfonso continued his career in various independent promotions. He served as a referee in Xtreme Pro Wrestling and took on roles as a referee and manager in Elite Wrestling Entertainment, Squared Circle Wrestling, and Pro Wrestling Unplugged. In May 2007, he joined Women's Extreme Wrestling, where he took on both managerial and commissioner duties.

Alfonso's legacy includes a memorable appearance at the Total Nonstop Action Wrestling (TNA) ECW reunion show, Hardcore Justice, on August 8, 2010, where he managed Rob Van Dam and Sabu. Additionally, in October 2002, a lawsuit from fellow manager Missy Hyatt over damages to her Porsche brought him into the spotlight of daytime television on Judge Mathis.

While Alfonso's family has a rich wrestling heritage, including his stepbrother, Olympian Bob Roop, and cousin David Sierra, he is often mistakenly linked to the late wrestler Mike Awesome, due to the shared surname and their time in ECW.