Jermaine Coleman was born in New York City. By the early 1990s, Maino found himself in the middle of a “drug related kidnapping,” that led to a 5-to-15 years prison sentence: “We didn’t really know what we were doing,” he recalls. “We had a great idea, I guess, but we wound up getting caught.” During his decade-long prison term, Maino began rapping as a result of boredom: “I’d be in the box for twenty-three hours a day, I just started rapping as something to do. I feel like hip hop kept me alive.” While listening to DJ Clue mixtapes featuring some of “Brooklyn’s Finest” – Notorious B.I.G, Jay-Z, Lil’ Kim – the vibe only got stronger. Maino adopted the “no writing” technique of emceeing: “I was never comfortable writing my raps down.” Upon his release in 2003, Maino immediately launched independent record label Hustle Hard Entertainment. After several mixtape releases and key guest features, in 2005 Maino was offered a recording contract by Universal Records. Maino split with the label in 2007.

In 2008, Maino later signed himself and his Hustle Hard imprint to Atlantic Records. He then began working on his debut album, If Tomorrow Comes…. His commercial debut single, titled “Hi Hater,” was released in April 2008. Maino later released the song’s official remix, featuring fellow American rappers T.I., Swizz Beatz, Plies, Jadakiss and Fabolous. The album’s second single was “All the Above,” featuring T-Pain. “All the Above” is Maino’s first song to chart on the Billboard Hot 100. It debuted at #54 and then rose to #39 the next week. It also had peaked at #10 on the Hot Rap Tracks, #59 on the Hot R&B/Hip-Hop Songs chart, and #46 on the Pop 100. The single is certified platinum and is Maino’s only Top 40 hit to date. The album’s third single “Million Bucks,” features vocals and production from Swizz Beatz. If Tomorrow Comes… debuted at number 25 on the Billboard 200 with first-week sales of 18,000 copies in the United States. In 2008, Maino also crafted an original song titled “Getaway Driver”, for the Grand Theft Auto IV video game.

On February 2, 2010, Maino released Unstoppable, exclusively through iTunes; an extended play (EP) which featured four new recordings. On July 5, 2011 Maino announced his second studio album, entitled The Day After Tomorrow, would still be pushed by Atlantic Records, but it would be distributed by E1 Music The album’s lead single “Let It Fly”, features Atlanta rapper-singer Roscoe Dash. It debuted on the US Billboard Hot R&B/Hip-Hop Songs at number 57. The Day After Tomorrow, unlike Maino’s debut album, had lower sales, debuting at number 94 on the Billboard 200. Through his label Hustle Hard, Maino formed a rap group called The Black Flag Mafia, which includes himself, Push!, Lucky Don, Twigg Martin and Hustle Hard Mouse. On October 9, 2012 they released their first mixtape, The Mafia. They are currently working on their EP album for E1 Music. On February 4, 2014, Maino will released a digital EP, King Of Brooklyn EP. In 2018 he did a duet with RRose RRome.

On September 12, 2010, Maino made a cameo on the MTV show World of Jenks where he infamously had an altercation with show host Andrew Jenks after a culture clash. This was said to be the most dramatic episode of World of Jenks. Though Maino clashed with Jenks, the two reconciled their differences at the end.

In 2015, Maino recorded “Crazy” with Erika Jayne which resulted in a number one dance hit in the US.

In the 2016 Irving Plaza shooting, he was cleared of any responsibility in the shooting with an NYPD Chief saying “We do not believe that he (Maino) was involved in the dispute.”