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 so she could study with tutors. In 2010, she created the original role of Miriam in the reading of the new musical, Cuba Libre, written and produced by Desmond Child. Grande played the character Cat Valentine on the Nickelodeon television show Victorious, which premiered in March 2010. It ended on February 2, 2013. Grande was also featured in Dream Magazine as the cover girl for the August 2.
In 2011, Ariana voiced an animated fairy, Princess Diaspro, on the Nickelodeon series Winx Club and starred as Snow White along with Charlene Tilton and Neil Patrick Harris in the Pasadena Playhouse production of A Snow White Christmas from December 13–23, 2012. In 2012, Grande sang a duet with MIKA on the single version of his track Popular Song.
In the following month it was also announced that Victorious's current season (Season 3, which was split to a fourth season) will be the last. Grande tweeted stating that she wasn't hoping for it to end and was looking forward to being on both shows. It was announced that the third soundtrack would be released on November 6, 2012 titled as Victorious 3.0. The first single was called "LA Boyz" (which was performed by Grande and Justice) and the music video was released October 18, 2012. It was announced during the network's presentation at the Television Critics Association Summer Press Tour on August 3, 2012 that Sam & Cat, which would pair Grande from Victorious and Jennette McCurdy from iCarly together in a traditional "buddy sitcom" setting, where they would reprise their roles as Cat Valentine and Sam Puckett. Sam & Cat was picked up by Nickelodeon on November 29, 2012.
Grande is working on her first studio album, Daydreamin', which is due for release in August 2013. Grande commented on the album saying: "They can expect a lot of honesty. It's like a direct... you know, it's like it used to be pages from my diary, instead of keeping diary, I would write songs about what was happening in my life. So it's really personal. It's a Motown throwback and pop at the same time, so it's '50s and '60s inspiration mixed with today." The album was inspired by artists like Amy Winehouse, Mariah Carey, Whitney Houston, Alicia Keys, Christina Aguilera, Katy Perry, Madonna and other like these. Grande worked with artists like Sky Blue from LMFAO, 3OH!3, Kool Kojak, and Pebe Sebert on the album. She was also working in the studio with Jonas Brothers singer Nick Jonas. It was stated by Grande in an interview that the second single from her debut album would be released around Valentine's Day of 2013, but never was. On March 20, 2013, Ariana previewed her new song in its entirety at B96 in Chicago for a small group of her dedicated fans and had a pizza party with them. On March 26, 2013, Ariana's first single off her debut album, "The Way" featuring Pittsburgh rapper Mac Miller, was released. The album's second single "Baby, I," will be released on July 22, 2013.
In 2012, Grande began dating Jai Brooks, a member of the Australian YouTube group the Janoskians. They had a long distance relationship until December 2012, when they met for the first time in New York City.