From sesameworkshop.org: 
“Emilio Delgado (Luis) can easily claim one of the longest running parts for a Latino actor in a continuing series as Luis on Sesame Street, since the show's third season. He began his career in the Emmy Award winning Canción de la Raza, followed by a memorable performance in the acclaimed I Will Fight No More Forever, and Ruben Castillo on the popular Lou Grant series. He also appeared on Cosby and Law and Order. He was Artistic Director of the Barrio Theatre Ensemble of East LA and a company member of Inner City Repertory and Group Repertory playing a multitude of roles. On Broadway, he understudied Raúl Julia in the musical Two Gentlemen of Verona. Film credits include Follow That Bird and The Adventures of Elmo in Grouchland. Recent NY Theatre credits are A Very Old Man with Enormous Wings, Shakespeare Company of New Jersey; Boxing 2000, NY City Players; Floating Home, Hudson Exploited Theatre Co.; The San Diego Street Padres, INTAR; and the award winning Dismiss All the Poets, NY Fringe Festival. Emilio is a recipient of the Impact Award from the National Hispanic Media Coalition and has been honored numerous times by the National Academy of Arts and Sciences for his work on Sesame Street. A talented singer and musician, he performs to sold-out audiences nationwide as Luis, and if you stay up past your bedtime, you might catch him on reruns of Quincy, Police Story, and Hawaii-5-O!”
- Delgado also wrote Spanish lyrics for the song "Sing," originally composed by Joe Raposo.
- Delgado was also the voice of Rosita's Abuela in Episode 4096. He also voiced an Anything Muppet boy singing a Spanish-English duet of the song "Me" with Marilyn Sokol.