Grande was born and raised in Boca Raton, Florida. She is of Italian descent, half Sicilian, half Abruzzese. In 2008, Grande played the role of Charlotte in the musical 13 on Broadway, for which she won a National Youth Theatre Association Award. When she joined the musical, Grande left her high school, North Broward Preparatory School, but continued to be enrolled. The school sent materials to her for study with tutors. She played the role of Miriam in the first reading of the forthcoming musical Cuba Libre composed by Desmond Child. Grande teaches music and dance to children in South Africa each year as a member of Broadway in South Africa.
Grande plays the character Cat Valentine on the Nickelodeon television show Victorious, which premiered in March 2010.
In May/June 2011, she was featured in Greyson Chance's music video for the single "Unfriend You", playing Chance's ex-girlfriend. she played in and as Victorious,Cat Valentine iCarly,Cat Valentine