Aarón Rodríguez Arellano is a Mexican luchador (professional wrestler). He is regarded as one of the greatest wrestlers of the lucha libre tradition in Mexico - along with El Santo and Blue Demon - and has been described as the first international superstar of lucha libre. Máscaras is considered one of the most influential wrestlers of all time for enhancing and popularizing the lucha libre style around the world, both in the ring and as the star of 20 films. He is also an accomplished artist and cultural ambassador for his native country and has appeared on three of its postage stamps. Although he has never been unmasked and his true identity is generally kept a secret out of respect for lucha libre traditions, his real name is known due to appearing in the credits of the films he has starred in. His ring name is Spanish for "Thousand Masks".

Máscaras was inducted into the Professional Wrestling Hall of Fame in 2010, and the WWE Hall of Fame in 2012. He is a member of one of Mexico's most prominent wrestling families; his brothers José and Pablo respectively wrestle as Dos Caras and Sicodélico. José's oldest son Alberto is a former WWE Champion and currently wrestles as Alberto El Patron. José's younger son Guillermo wrestles as El Hijo de Dos Caras. Pablo's son Aaron is better known as Sicodelico Jr.