World Extreme Cagefighting

On March 26, 2008, Stann defeated Doug Marshall via KO to become the WEC Light Heavyweight champion. With this victory, Stann's MMA record reached 6–0, with five victories in the WEC.

In August 2008, Stann lost his title in his first defense, in a rematch against Steve Cantwell (a loss he avenged a year later).^[9]

Ultimate Fighting Championship

In 2008, Zuffa announced plans to merge the WEC's 185-lb and 205-lb weight classes with their UFC counterparts, allowing the WEC to concentrate on lighter weight classes (which eventually merged with the UFC as well).^[10]

Stann was scheduled to make his UFC debut on December 10, 2008, at the UFC: Fight For The Troops show, to be held at the Army base of Fort Bragg, North Carolina, but he was forced to withdraw from the card due to a foot injury sustained in training.^[11] Instead, he faced Krzysztof Soszynski at UFC 97 in Montreal, Quebec, Canada, on April 18, 2009. In the first round, Soszynski locked Stann in a kimura, forcing him to tap out for the first time in his career. Stann later stated in an issue of UFC Magazine that, because of previous military commitments, he was unable to adequately prepare himself for the "grappling-based" aspects of the fight, which contributed to his loss.

On September 16, 2009, at UFC Fight Night: Diaz vs. Guillard, Stann once again faced Steve Cantwell in a rubber match. Stann would go on to defeat Cantwell via unanimous decision (30–27, 30–27, 29–28). This would also be the first time he would fight to a decision in his professional career.

Stann defeated UFC newcomer Rodney Wallace on December 5, 2009, at The Ultimate Fighter 10 Finale by unanimous decision.^[12]

Stann then faced UFC newcomer Phil Davis on February 6, 2010, at UFC 109,^[13] losing via unanimous decision. Following the fight, Stann revealed he would drop to the 185 lbs. Middleweight division.

Stann then made his middleweight debut against Mike Massenzio on August 1, 2010, at UFC on Versus 2.^[14] Stann claimed his first ever submission victory, catching Massenzio in a triangle choke midway through the final round, in a bout that earned Fight of the Night honors.

Stann then fought in the co-main event of UFC 125 on New Years Day. He defeated Chris Leben with a first-round TKO stoppage. With this win, he became the second man to defeat Leben by way of strikes, the first being former UFC Middleweight Champion Anderson Silva.

Stann was scheduled to face former Pride Middleweight Champion Wanderlei Silva on May 28, 2011, at UFC 130.^[15] However, Silva voiced his reluctance to face Stann and was replaced by former Sengoku Middleweight Champion Jorge Santiago. Stann defeated Santiago via TKO in the 2nd round. A right to the temple sent Santiago to the mat, followed by numerous strikes by Stann which forced the stoppage.^[16]

Stann then fought Chael Sonnen on October 8, 2011, at UFC 136^[17] where he was defeated via second round submission.

Stann faced Alessio Sakara on April 14, 2012, at UFC on Fuel TV: Gustafsson vs. Silva.^[18] After knocking down Sakara early with knees from the clinch, Stann utilized heavy ground-and-pound, delivering short elbows and hammerfists that eventually knocked Sakara out. Stann was awarded the victory at 2:26 of the first round. After Stann delivered the knockout blow, he sat up and motioned to the ref that Sakara was out, rather than delivering unnecessary (and potentially damaging) blows before the ref could jump in and stop the fight. Stann's actions were highly praised by both the media and fighters, with UFC Light Heavyweight Champion Jon Jones being quoted as saying that Brian Stann's actions were "good for the sport." UFC president Dana White also issued his praise for Stann's actions in the cage, calling him "one of the classiest people on Earth!".^[19]

Stann was expected to face Héctor Lombard on August 4, 2012, at UFC on Fox 4.^[20] However, Stann was forced out of the bout, citing a shoulder injury.^[21]

Stann next faced Michael Bisping on September 22, 2012, at UFC 152, losing by unanimous decision.^[22]

On March 3, 2013, at UFC on Fuel TV 8, the long-awaited fight between Stann and Wanderlei Silva happened, in a Light-Heavyweight division showdown.^[23][24] Stann lost the fight via KO in the second round, in a bout that featured back-and-forth action, earning both participants Fight of the Night honors.^[25][26]

On a special edition of Ariel Helwani's MMA Hour on July 11, 2013, Stann announced his retirement from mixed martial arts competition.^[27] Upon retiring, Stann became an analyst and commentator for Fox Sports and UFC.^[28] In August 2017, Stann announced that he would be leaving his job with Fox and UFC to become a real estate executive.^[29]

Professional Fighters League

In May 2018, ESPN reported that Stann accepted the advisory role as the head of Fighter and Competition/Rules Committee in the advisory board of Professional Fighters League (PFL), formally known as World Series of Fighting, where PFL would launch its inaugural season on July 7, 2018, airing on NBC Sports. Stann's main responsibility in the role would be influencing PFL on tournaments management, treatment and recruitment of the fighters. As per the report, Stann did not anticipate this new opportunity with PFL prior to leaving his commentary position with Fox Sports and the UFC.^[30]

Mixed martial arts

• World Extreme Cagefighting
  • WEC Light Heavyweight Championship (One time)
• Ultimate Fighting Championship
  • Fight of the Night (Three times) vs. Mike Massenzio, Jorge Santiago and Wanderlei Silva
• MMAFighting.com
  • 2013 Best Fight of the Half-Year vs. Wanderlei Silva^[33]
• CombatPress.com
  • 2015 Broadcast Analyst of the Year^[34]

United States military

• Awards and decorations of the United States military
  • Silver Star