Born in Maracaibo, Venezuela, Velásquez, the fifth of six children, was the daughter of Venezuelan parents. Her father is mestizo and her mother a member of the Indigenous Wayuu people. Her parents were both teachers; her father also worked for UNESCO and as a result, she spent some of her childhood in Mexico and France. She attended San Vicente de Paul High School, graduating in 1987. In 1989, she participated in the Miss Venezuela pageant, where she took 2nd place (2nd finalist). After 3 years of college studies, Velásquez left for Milan, Italy, in pursuit of a modelling career.
Velásquez played the character of Begoña on several episodes of The L Word during its 5th season (2008). She had a recurring role on the television series Arrested Development playing Marta Estrella. On CSI: Miami, in the episode "From The Grave", she appeared as a guest star, playing Celia Gonzalez. She had a recurring role in the first season of Rescue Me playing Nez, the ex-girlfriend and mother of Franco's daughter, Keela. She most recently guest starred on Ugly Betty.
Velásquez competed on behalf of the charity the Wayúu Tayá Foundation on the twelfth season of The Apprentice. She was fired in week 6, on March 25, 2012.
In 2002, Velásquez founded the Wayúu Tayá Foundation, a non-profit organisation dedicated to assisting the Wayúu, a Venezuelan indigenous group. In 2010, after the devastating Haiti earthquake, she had the Wayuú Tayá Foundation commission a special symbol of hope to raise money for the victims of the Haiti earthquake along with the slogan: Keep the "H" Close to Your Heart—Help Haiti Hope. She is fluent in English, French, Italian, and Spanish.