Gomez, an only child, was born in Grand Prairie, Texas.
Her father, Ricardo Gomez, is from Mexico and her mother, Mandy Teefey, is of half Italian descent.
She was named after Tejano music singer Selena and has met her family.
Her mother is a former stage actress.
Gomez began her acting career at the age of seven, where she spent her birthday at an open casting call competing with thousands of others for a role in the hit children's television series Barney & Friends.
She was cast as a recurring character named Gianna in seasons seven and eight.
Gomez appeared in national commercials for several companies including Wal-Mart, Hasbro and T.G.I. Friday's.
In 2003 she was cast in the movie Spy Kids 3D for a small role. She made a small appearance in Walker, Texas Ranger: Trial By Fire and played Emily Garcia in the movie, Brain Zapped.
In 2004 Gomez was discovered by Disney.
She appeared in the Disney's The Suite Life of Zack & Cody as Gwen. Subsequently, she appeared in the second season of Disney's Hannah Montana as Hannah Montana's rival, Mikayla.
In 2007, Gomez was cast in the lead role Alex Russo in the Disney Channel Original Series, Wizards of Waverly Place.
A second season was ordered. In 2008, Gomez was involved in two feature films.
The first, was a voice-over of the Mayor's 96 daughters, in the animated film, Horton Hears a Who!. The second was a sequel to A Cinderella Story, Another Cinderella Story. That same year, she was cast as Carter, an insecure tomboy in the upcoming Disney Channel Original Movie, Princess Protection Program alongside Demi Lovato.