Maurice "Mo" Smith (born December 13, 1961) is an American professional kickboxer, mixed martial artist and former Ultimate Fighting Championship heavyweight champion.After a stint in Japanese promotions Pancrase and RINGS, accumulating a 4-7 record, Smith joined Battlecade Extreme Fighting in 1996 to fight in their third event against the heavyweight champion Marcus Silvira "Conan".

Throughout the fight Maurice showed excellent use of the sprawl technique which negated the Brazilian Jiu-Jitsu man's attempts at takedowns before knocking Conan out in the third round with a kick to the head.

In doing so he became the first legitimate striker to win a top end MMA event. He then defended his title in the forth show against judo exponant Kazunari Murakami, this time Maurice won with a first round knockout. After that the company went under and Maurice went to the UFC. At UFC 14 on July 27, 1997, he defeated Mark Coleman via unanimous decision to win the UFC heavyweight championship. He successfully defended his belt against David Abbott "Tank" winning via strikes, before losing his belt to Randy Couture due to a controversial decision.

On May 19, 2007 Maurice Smith had his first MMA bout in almost seven years when he defeated Marco Ruas by TKO at an International Fight League show held in Chicago. On February 23, 2008 at a Strikeforce event entitled Strikeforce: At The Dome held at the Tacoma Dome in Tacoma, Washington, Smith defeated kickboxer Rick Roufus, who was making his MMA debut, by submission at 1:53 of the first round.

Maurice Smith was the coach of the Seattle Tiger Sharks of the International Fight League from 2006 to 2007. He is currently associated with Team Alliance.