Dante Terrell Smith (born December 11, 1973), better known by his stage name Mos Def, is an American MC and actor. Mos Def acquired his stage name from his frequent use of "mos def" in place of the words "most definitely".

Mos Def started his hip hop career in a group called Urban Thermo Dynamics, after which he appeared on albums by Da Bush Babees and De La Soul. With Talib Kweli, he formed the duo Black Star, who released the well-received album Black Star in 1998. He was a major force in the late 1990s underground hip hop explosion spearheaded by Rawkus Records. As a solo artist he has released the albums Black on Both Sides in 1999, The New Danger in 2004, and True Magic, 2006.

Initially recognized for his musical output, Mos Def's screen work since the early 2000s has established him as one of only a handful of rappers who have garnered critical approval for their acting work. He has been nominated for Golden Globe, Emmy, and Grammy Awards. Mos Def has also been active on several social and political issues, and was particularly vocal in the wake of Hurricane Katrina in 2005.