Roselyn Sánchez was born in San Juan, Puerto Rico. At a very young age, she showed an interest in both dancing and acting. In 1991, at the age of 21, Sánchez moved to New York City, where she took classes in dancing, acting and singing. She returned to Puerto Rico, and in 1992 she made her movie debut, having landed a small part as an island girl in the movie Captain Ron, which was partly filmed in Puerto Rico, starring Martin Short and Kurt Russell.

In Puerto Rico, she gained public attention as a dancer and as co-host of a variety show called Que Vacilon. At that time, in 1993, Sánchez won the Miss Puerto Rico Petite contest, and in 1994 she won the international title of Miss American Petite, bringing her international fame. Sánchez has been named to numerous annual lists of beautiful women including Maxim Magazine's "Hot 100" in 2001, 2002 and 2006; AskMen.com's "Top 99 Most Desirable Women" in 2005 and 2006; and FHM Magazine's "100 Sexiest Women" in 2005 and 2006.

In 2001, Sánchez was cast as Isabella Molina, an undercover United States Secret Service agent who was Jackie Chan's love interest in the hit movie Rush Hour 2. In 2003, she played the role of Lorena in the movie Chasing Papi, starring alongside Jaci Velasquez and Sofia Vergara. Sánchez has acted in some 20 movies, including as Maria in Edison and as Karen Lopez in Underclassman. She also starred in the Puerto Rican film Cayo, released in 2005. Also in the fall of 2005, she joined the cast of the television series Without a Trace, where she plays Agent Elena Delgado.

She composed the musical Yellow, about a singer/dancer/actress who leaves Puerto Rico to hit the big time in New York, in which she played the principal part. Also in 2007, she acted as Monique, Peyton's ballet teacher, in The Game Plan, and appeared in the movie Venus & Vegas.

In 2003, her first musical recording, Borinqueña, was released. The album's first single, "Amor Amor", gained a lot of attention as well as a Latin Grammy nomination for Best Music Video. She appeared in Craig David's music videos "Hidden Agenda" and "Personal" and in the Fabolous video for the song "Make Me Better".