Omari Ishmael Grandberry (born November 12, 1984), better known by his stage name Omarion, is an American R&B singer, dancer and actor. He rose to prominence as lead vocalist of the boy band B2K, which was formed in 1998 and managed by record executive Chris Stokes. The group achieved success in the early 2000s with their singles "Gots ta Be", "Uh Huh", "Girlfriend", and the Billboard Hot 100-number one hit "Bump, Bump, Bump" (featuring P. Diddy).

After the group's 2004 disbandment, Omarion promptly embarked on a solo career. He signed with Epic Records to release his first two studio albums, O (2005) and 21 (2006), both of which debuted atop the Billboard 200. The former was led by the Billboard Hot 100-top 40 single "O" and was nominated for Best Contemporary R&B Album at the 48th Annual Grammy Awards, while the latter spawned the single "Ice Box", which remains his highest-charting song at number 12. Omarion guest appeared on Bow Wow's single "Let Me Hold You", which peaked at number four on the Billboard Hot 100; the artists released the collaborative album, Face Off (2007), followed by Omarion's third studio album, Ollusion (2010), both of which saw moderate commercial response. He signed with Rick Ross' record label Maybach Music Group to release his fourth album, Sex Playlist (2014). It was preceded by the single "Post to Be" (featuring Chris Brown and Jhené Aiko), which peaked at number 13 on the Billboard Hot 100 and received sextuple platinum certification by the Recording Industry Association of America (RIAA).

Omarion has also ventured into acting, with appearances in films such as You Got Served, Fat Albert, Somebody Help Me and The Proud Family Movie. As a solo artist, he has received a BET Award, a Billboard Music Award, and a Soul Train Music Award.