Mario who is African American was born in Baltimore, Maryland, and grew up in Pikesville, Randallstown, Gwynn Oak and other working-class neighborhoods in Baltimore, Maryland. He grew up with his grandmother in different areas of Baltimore, Maryland, she also raised him while his single mother struggled with a drug addiction. Mario said at the age of four that he wanted to become a singer. His mother supported his dream and bought him a karaoke machine. Mario joined a musical group in high school with the oldest son of comedienne Mo'nique. He was always dedicated to having a musical career. He learned to play the piano and used that skill as the basis for his melodies and songs. He was discovered at age eleven and signed by producer Troy Patterson , after singing "I'll Make Love to You" at a Coppin State College talent show. Mario attended Milford Mill Academy up until the tenth grade where he was inspired by his music teacher, during his early teen years, and was offered a record deal at the age of fourteen, signing with Clive Davis' J Records. His musical influences include Stevie Wonder, Fernando, Q-Bah, Claire and Shay all from FunX radio Marvin Gaye, Sam Cooke, Nat King Cole, Brian McKnight, Boyz II Men, Usher, and Joe. His first introduction to the music industry was the Dr. Dolittle 2 movie soundtrack in 2001. He sang a captivating performance of the Stevie Wonder classic "You and I" at Clive's Grammy party in 2002, and began recording an album.
MTV aired a special on October 21, "I Won't Love You to Death: The Story of Mario and His Mom," which dealt with his mother's heroin addiction. The documentary is about how the singer strives for help to stop his mother's addiction. While doing this, he seeks help from family and friends. Mario wrote a letter to his mother stating how appreciative he is and begs her to stop her addiction. At the end of the letter he says, "I love you, but I won't love you to death". The documentary, produced by Gigantic! Productions, won a 2008 Prism Award for its accurate portrayal of drug abuse .
Mario has also written a song titled Do Right that is dedicated to his mother. This song explains his mother's addiction and how it affected his childhood, and highlights how much he looks up to her. The song is featured on his third album Go.
Mario began recording his debut album Mario. A year before releasing it in July 2002. The lead single "Just a Friend 2002" , which was a cover of Biz Markie's hit, was an instant success, peaking at #4 on the charts. Follow up singles were "Braid My Hair" & "C'mon" . He was the opening act on the Scream Tour 3, which featured Lil' Zane, Bow Wow, Nick Cannon, B2K & Marques Houston. As of 2006, his debut album has sold over 700,000 copies. During this period, he became a draw in the teen market.
After his debut album was released, Mario wanted to record an album that was more mature. He enlisted a number of well-known producers to help him, such as Scott Storch & Lil' Jon. He released his second album, Turning Point on December 7, 2004. The album was more successful than his first, mainly because of the hit single "Let Me Love You". The single, described by reviewers as "melodic and sweetly lilting, reminiscent of Michael Jackson's vintage romantic ballads" was successful, peaking at the number one on the Billboard Hot 100 for nine consecutive weeks. The single is written by Ne-Yo. Other follow up singles include "How Could You" co-written by J. Valentine, with a cameo appearance in the video by rapper Cassidy; "Here I Go Again"(whose video starred model/singer Cassie; and "Boom" featuring Juvenile. To date, Turning Point has sold platinum and the lead single double-platinum.
In February 2006, Mario filed a lawsuit against his former manager, Troy Patterson, alleging that Patterson had paid him $50,000 for the sale of more than 3 million records. Mario's new manager is J. Erving and he was chosen by Mario. Mario has homes in Baltimore, Atlanta and Los Angeles.
Mario's third album Go! is dedicated to his mom Shawntia Hardaway and was released in South Africa under Gallo Records on October 9, 2007, in the U.S. on December 11, 2007. The album includes collaborations with Jermaine Dupri, Ne-Yo, Janice Robinson, Eric West, Lionell Davis, Scott Storch, Jimmy Jam and Terry Lewis, Timbaland, Bryan-Michael Cox, The Neptunes, Jim Jonsin, Akon, Dre & Vidal, Warryn "Baby Dubb" Campbell, Sean Garrett and Mr. Collipark. Mario, who has described the album as "sex...more personal...more passionate", had more creative control on Go than on his previous two albums. The first single to be lifted from the album was "How Do I Breathe" which was released in May. The second single was "Crying out for Me" after a poll on his website. The single was later certificated Gold by the RIAA. On December 13, 2007, Mario was on "106 & Park" where he stated that the third single off the album will be "Music For Love". The entire album was made available for the public to listen to on his Myspace page before its release. He also has a new song that came out on December 11, "Do Right". Go! has sold 331,540 copies in the U.S.
In an interview with DJ "Z", Mario stated that problems with the record label caused the album launch to be pushed back 6–8 months.
Before the release of his third album Go! on 21 December 2007. In an interview to Billboard Mario confirmed that he was working on a new album "by the time school starts back up, like after next summer” “But there's really even more than that, 'cause I'm gonna start recording, like, [at] the end of January". While the album is being released with different producers including Darkchild, Babyface, Polow da Don, RedOne, CJ of Charlio Productions, Malay, Jazze Pha, Stargate, KP, Tricky Stewart and The-Dream as confirmed by Mario. Mario said that he would like to work with no more than 4 producers for this album. Mario has described this album as World music, an old school R&B influenced with a modern dance pop sound. The album is being described as his “most personal, colossal album of his career.” In a Saynow message on Sept 14th 2008 from Mario he revealed that the new album is halfway done and he is finishing up the rest in a studio in L.A. he also sang a snippet of one of his new songs.
Mario stated that the album will be released in March or April 2009. However on March 7, 2009 in an interview Mario confirmed that the album was originally be released in June which it's release date now is set to September 22, 2009 according to his website. The first single is called "Break Up" and was released on 28 April, 2009.