Rivera's first feature role was in the TV series Renegade with Lorenzo Lamas. He also had a role in the feature film Con Air, co-starring Nicolas Cage. Emilio has appeared in several commercials, television programs and feature films including Traffic, The Cable Guy, NYPD Blue, Beverly Hills, 90210, Walker, Texas Ranger, Hitman: Agent 47, JAG, ER, A Man Apart with Vin Diesel, John Cusack's film Never Get Outta the Boat, Friday After Next, Ali G Indahouse, Rush, Howard Stern's Son of the Beach, Law and Order: Special Victims Unit, Z Nation, and Michael Mann's new series Metro. He also played Marcus Álvarez in Sons of Anarchy for the seven seasons and appears as Bodega Diablo Next Day Air. In 2013, he co-starred in the music video of rapper/singer Nicki Minaj's "High School" single. He played a secondary character on the 11th episode of the 2nd season of My Name Is Earl. In 2018 he played the lobby guard in Venom.