Óscar Gutiérrez (born December 11, 1974), better known by his ring name Rey Mysterio, is an American professional wrestler currently signed to WWE, where he performs on the Raw brand. According to ESPN, he is "widely regarded as the greatest cruiserweight in pro wrestling history".
Gutiérrez was born and raised in Chula Vista, California, and began his professional wrestling career at age 14 in 1989, prior to debuting for Mexican promotion Asistencia Asesoría y Administración (AAA) in 1992, under the tutelage of his uncle, Rey Misterio. He had a brief stint in Extreme Championship Wrestling (ECW) in 1995, before he signed with World Championship Wrestling (WCW).
In WCW, Mysterio helped popularize the high-flying lucha libre wrestling style, which is credited with having also helped kick-start the emergence of cruiserweight wrestling in the United States. He also won a number of championships during his time with the company, including the WCW Cruiserweight Championship and the WCW World Tag Team Championship. After WCW closed in 2001, Mysterio returned to Mexico, briefly wrestling for Consejo Mundial de Lucha Libre (CMLL), before signing with WWE in 2002.