Óscar Gutiérrez Rubio (born December 11, 1974), better known by the ring name Rey Mysterio, is a Mexican-American professional wrestler who currently works for Asistencia Asesoría y Administración (AAA). He is best known for his time in WWE. He is also known for his work in Extreme Championship Wrestling (ECW) and World Championship Wrestling (WCW). Gutierrez was trained by his uncle Rey Misterio, Sr., learning the Lucha Libre high flying style that has been his trademark.
Gutierrez originally worked for AAA in Mexico, from 1992 to 1995. He wrestled in ECW from 1995 to 1996 and WCW from 1996 to 2001 as Rey Misterio Jr. or Rey Mysterio Jr. ("Rey Misterio" is Spanish for "King Mystery"), but dropped the "Junior" from his name when he began working for WWE in 2002.
Mysterio is known for having a high flying style, which helped kick-start the cruiserweight wrestling revolution in the United States in the late 1990s during his time in WCW, and is often regarded as one of the greatest high-flyers in wrestling history. In WCW he won the WCW World Tag Team Championship three times, and the WCW Cruiserweight Tag Team Championship once with Billy Kidman as part of the Filthy Animals. In WWE, Mysterio is a three-time world champion, having held the World Heavyweight Championship twice and the WWE Championship once, and is currently listed as the lightest world champion in WWE history. He has also held the WWE Tag Team Championship a record-tying four times, and the WWE Intercontinental Championship twice. He also held the WCW/WWE Cruiserweight Championship a record eight times (five times in WCW, three times in WWE). All totaled, he has won 21 titles between WWE and WCW. Mysterio was the 21st person to win the WWE Triple Crown Championship, and was the winner of the 2006 Royal Rumble.
- Asistencia Asesoría y Administración Mexican National Trios Championship
- Asistencia Asesoría y Administración Mexican National Welterweight Championship
- Hollywood Heavyweight Wrestling Light Heavyweight Championship
- International Wrestling All-Stars Tag Team Championship
- International Wrestling Council World Middleweight Championship
- WCW / WWE Cruiserweight Championship
- WCW Cruiserweight Tag Team Championship
- WCW World Tag Team Championship
- World Wrestling Association Lightweight Championship
- World Wrestling Association Tag Team Championship
- World Wrestling Association Welterweight Championship
- World Wrestling Council World Junior Heavyweight Championship
- WWE World Heavyweight Championship
- WWE Championship
- WWE Intercontinental Championship
- WWE Tag Team Championship - WWE SmackDown Tag Team Championship
- WWE United States Championship