Mario Dewar Barrett was born in 1986 in Baltimore, Maryland and is known in R&B as Mario. He was raised by his grandmother in various parts of Baltimore, Maryland, as she also helped Mario's mother who was suffering from a drug problem. From an early age, Mario was eager to become a musician.

In high school, Mario formed a group with the son of comedienne Mo'nique. He played piano and attracted the attention of musical producers almost right from the start. At eleven, he was signed by producer Troy Patterson who heard Mario sing "I'll Make Love To You" at a Coppin State College talent show. At fourteen, Mario was signed to J Records and had his first public release with a song on the Dr. Dolittle 2 soundtrack in 2001.

Mario started recording his debut album, the self-titled Mario at the age of fifteen. The opening single to the album was "Just A Friend 2002," a cover of the track by Biz Markie that reached #4 on the Hot 100 and #3 on the R&B charts. Mario followed the single with "Braid My Hair" and "C'mon," neither of which could capture the success of his earlier single. "Braid My Hair" reached #18 on the R&B charts while "C'mon" peaked at #61. With the help of his three singles, Mario's debut was certified gold.

In 2004, Mario released his sophomore album, Turning Point. Mario sought to make a maturer album and teamed up with Scott Storch and Lil' Jon to help. The album featured Mario's biggest hit, "Let Me Love You" which topped the Hot 100 and R&B charts. The later singles weren't as successful, but "How Could You" and "Here I Go Again" both charted well, reaching #14 and #9 on the R&B charts respectively. The single "Let Me Love You" was successful enough to go platinum, and helped drive the album to comparable sales as well.

Mario's third, and latest release thus far, Go, was released in 2007. The album was dedicated to his mother, Shawntia Hardaway. The album was ripe with collaborations, featuring work from Jermaine Dupri, Ne-Yo, Scott Storch, Jimmy Jam and Terry Lewis, Timbaland, Bryan-Michael Cox, The Neptunes, Dre & Vidal and many others. The album's two singles both reached the top 20 on the R&B charts, with "How Do I Breathe" reaching #18 and "Crying Out for Me" reaching #5.

Mario hopes to have a fourth album released in 2008. Some of the work for this album is being done by Knightwritaz, a production team that Mario is a part of. The group, comprised of Mario, Sterling Simms, Warren "Oak" Felder and Marsha of Floetry have done production for Jennifer Lopez, Chris Brown and Raven-Symone.

On a different note, Mario actually appeared on the show Dancing With The Stars. He danced with Karina Smirnoff and together, they reached the eighth week before being knocked off.