Legal name: Dante Smith
Mos Def (/ˈmoʊs ˈdɛf/); born Dante Terrell Smith; December 11, 1973), also known by his recently used stage name Yasiin Bey (/jæˈsiːn ˈbeɪ/), is an American hip hop recording artist, actor, comedian, and activist from Brooklyn, New York City, New York. Best known for his music, Def embarked on his hip hop career in 1994, alongside his siblings in the short-lived rap group Urban Thermo Dynamics (UTD), after which he appeared on albums by Da Bush Babees and De La Soul. He subsequently formed the trio Black Star, alongside fellow Brooklyn-based rapper Talib Kweli, and Cincinnati producer Hi-Tek and released their eponymous debut album in 1998. He was a major force in late-1990s underground hip hop while under Rawkus Records. In 1999, Def released his solo debut, Black on Both Sides, under Rawkus and Priority Records. His debut was followed by The New Danger (2004), True Magic (2006) and The Ecstatic (2009). The editors at About.com listed him as the 14th greatest emcee of all time on their "50 greatest MC's of our time" list.
Prior to his career in music, Def first entered public life as a child actor, having played roles in television movies, sitcoms, and theater, some of which were under the name Dante Beze. At the age of 14, he appeared in the TV movie God Bless the Child, which aired on ABC in 1988. He played the oldest child in the 1990 family sitcom You Take the Kids, shortly before it was cancelled. In 1995, he played the character "Dante" in The Cosby Mysteries. Since the early 2000s, Def has been well known for his roles in films such as Something the Lord Made, Next Day Air, The Hitchhiker's Guide to the Galaxy, 16 Blocks, Be Kind Rewind, The Italian Job, Bamboozled and Brown Sugar, as well as for his portrayal of Brother Sam in the Showtime drama series Dexter. He is also known as the host of Def Poetry Jam, which aired on HBO between 2002 and 2007.
Def has been vocal on several social and political causes, including police brutality, the idea of American exceptionalism, and the state of African Americans.