Gabriella Montoya Montez is a beautiful and intelligent girl who was a student of East High, where she attended school with all her friends. She is known for being one of the smartest girls at East High, even taking college courses at Stanford University before even finishing high school; for her musical talent, such as in the musicals with Troy and just singing in general; and for being the girlfriend of popular basketball star of the school, Troy Bolton. Gabriella is kind, smart, and practical. She studies law at Stanford University.
She is the only child of Mr. and Mrs. Montez. Extraordinarily beautiful and academically-gifted, she meets Troy at a family bar during their winter break and are forced to sing in the New Year's Eve party at the Ski Mountain Resort. Upon singing with each other ("The Start of Something New"), they instantly feel a connection with one another, and, as fate would have it, they end up attending the same school, East High. There, they become close friends, and eventually begin dating. When the two meet up at the auditions for the winter concert, they try out for the callbacks and do a duet of a song called Breaking Free. Since Troy, being the basketball star of East High and not known to have a passion or talent for singing, and Gabriella, the shy, nerdy new girl with a liking for chemistry, start singing, there is a large amount of social unrest at the school, as more people begin revealing their passions that conflict with the stereotypes they have been placed into. However, despite numerous attempts to break the duo apart, they end up singing the duet and encouraging others to break from the norm in favor of following their dreams. Following the performance, the two become a very successful couple, though not without their occasional conflicts. Eventually, Sharpay Evans is jealous of Gabriella because of how popular Gabriella is becoming in the school, which Sharpay sees as a threat to her own popularity.
Gabriella has maintained her romance with Troy, and the couple, along with their friends, get jobs at the Lava Springs Country Club. Gabriella takes the position of a responsible and adept lifeguard. However, Sharpay gets angry because she bribed Fulton to get Troy Bolton a job--not the entire East High. Seeking revenge, Sharpay lures Troy away from Gabriella and his friends, showering him with various luxuries, including promising college opportunities. She even sings him a song ("Humuhumunukanukakap'ua") complete with lights, a set and a whole onstage performance in an attempt to win over Troy, and makes him promise to sing with her. After Troy repeatedly breaks his promises and backs out of his commitments, Gabriella breaks up with him and quits her job at Lava Springs, claiming that working together sounded good, but is too hard now given their recent issues. During this scene Gabriella belts out "Gotta Go My Own Way," and drives away with her mother at the end, leaving Troy heartbroken and giving back the T necklace. However, the two of them reunite at the end after Troy apologizes to his friends, gets his job back, confronts Sharpay and learns a new song--a duet he and Gabriella sing at the talent show, entitled "Everyday."
A Stanford-bound Gabriella is uneasy about the fast pace her life has taken. Before graduation, Gabriella briefly considers taking classes at the local university for a year and going to Stanford when she is ready, much to the dismay of Taylor and Mrs. Montez. Troy urges Gabriella to accept an early orientation. Gabriella goes to Stanford but must drop out of the school musical (allowing Sharpay to fill the lead role) and miss prom. Wanting his last dance at East High to be with Gabriella, Troy drives to Stanford and the two share an intimate prom of their own. He convinces Gabriella to return to East High for opening night of the musical and for graduation. Gabriella sings in the spring play, and her classmates put together a surprise reunion complete with gifts, hugs, and flowers for Gabriella onstage during the performance of "Just Wanna Be with You." Gabriella will attend Stanford and study law. She put her house up for sale before she graduated high school.
- She is the youngest of the High School Musical, High School Musical 2 and High School Musical 3: Senior Year groups.