Monica Pauline Gil (aka Nikki Gil) was born in Manila to Dino and Julie Gil. She is of Filipino, Spanish and German descent. Born to a father who plays the piano and a mom who sang in a church choir, Nikki showed early signs of musical talent. At the age of four years, Nikki was already singing and doing voiceovers for commercials. She graduated from Shekinah Christian Training Center in March 2005 as valedictorian. In 2009, she graduated from Ateneo de Manila University, majoring in English literature.
Gil first rose to prominence when she was 17 years old after appearing in a 2005 Coca-Cola commercial. After that, she went on to released her first self-titled album, Nikki Gil, that same year under EMI Philippines with "Sakayan ng Jeep" as the carrier single. In 2006, it was repackaged and rereleased with and additional song, "Glowing Inside". In July 2006, EMI Philippines and Walt Disney Records hired Nikki along with other Asian artists (Vince Chong of Malaysia and Alicia Pan of Singapore) to sing and to star in the music video of "High School Musical", a Disney Channel production. Nikki also sang "Breaking Free" and "Gotta Go My Own Way" in the production's album.
In 2005, Gil was given a VJ stint for ABS-CBN's music channel subsidiary, MYX until she left MYX in January 2016. She was also picked to host the now-defunct talk show MRS on ABS-CBN and morning show Breakfast on Studio 23. She later would join the cast of the weekly variety show ASAP Mania. In 2006, she was joined by Toni Gonzaga, Bianca Gonzalez and Sam Milby as a host for the first season of Pinoy Dream Academy, a singing reality show from Endemol. In 2007, she became part of an anime-inspired fantasy series "Rounin" and as an extended cast for the drama series "Pangarap na Bituin". In 2008, she was again chosen to be the host for the season 2 of Pinoy Dream Academy with Toni Gonzaga and Billy Crawford. In 2009, she appeared in "Pieta", an afternoon teleserye with Ryan Agoncillo, and also appeared in the teleserye "Florinda" with Maricel Soriano. Nikki Gil is one of the mainstay on ABS-CBN with ASAP XV. In 2010, she started hosting E-Live along with Luis Manzano and Ogie Diaz. She also did a fair share of hosting occasionally on Showtime replacing Anne Curtis.