Dennis Siver is a German mixed martial arts fighter currently competing in the UFC featherweight division. He formerly competed in the UFC lightweight division. He is known for his deadly use of the spinning back kick, with which he defeated Paul Kelly and Nate Mohr.
He won his most recent fight versus heavy-handed brawler Spencer Fisher via unanimous decision despite a hefty cut being opened over Siver's left eye early in the first round by an accidental headbutt.
He was rumored to be next set to face former Pride lightweight champion Takanori Gomi. He instead faced Andre Winner, defeating him via first-round rear-naked choke submission after dropping Winner with punches. Siver next took a big step up in competition to face contender George Sotiropoulos. Siver defeated Sotiropoulos via an upset unanimous decision victory.
He next faced his third straight Ultimate Fighter veteran, defeating Matt Wiman via controversial unanimous decision.
Siver was next set to face fellow striker Sam Stout, but Stout was injured well before the bout was scheduled and he was forced to pull out. He was replaced by WEC veteran Donald Cerrone. Cerrone defeated Siver via dominant first round rear-naked choke submission.
After the violent loss, Siver dropped down to the featherweight (145 pounds) division. He was rumored to make his debut in a rematch against TUF winner Ross Pearson. Instead, he signed to face exciting contender Diego Nunes. He defeated Nunes via a very close and exciting decision.
Siver next signed to face the tough fan favorite Eddie Yagin. Yagin was hospitalized with swelling around his brain after a training injury and he was replaced on relatively late notice by veteran Nam Phan. Siver defeated Phan via dominant unanimous decision and quickly resigned to face fellow contender Cub Swanson in London, England. The fight would be for a title shot against the winner of the featherweight title fight between Jose Aldo and Frank Edgar.
Unfortunately Siver was injured mid-January 2013 and replaced by contender Dustin Poirier.
After recovering, Siver next signed again to face Swanson. Swanson defeated Siver via a third round technical knockout after a back-and-forth war. Many suspected that the weight cut had affected Siver negatively, as he had dominated the fight's first round on the mat and on the feet.
Siver next signed to fight Manny Gamburyan for December 2013. Siver defeated Gamburyan via a close but unanimous decision.
Siver next called out Dustin Poirier for UFC 172 in spring 2014 but fellow featherweight contender and former lightweight veteran Jeremy Stephens answered the call. Stephens stated that he'd love to fight Siver at UFC 172.
The fight never materialized and Siver was also suspended after testing positive for banned substances after the Gamburyan fight. The win over Gamburyan was also overturned to a no-contest.
Siver next signed to fight Robert Whiteford after his suspension was up. A few more opponents were shuffled in confusion before newcomer Charles Rosa stepped up. Siver beat Rosa by unanimous decision after a great competitive fight.
Siver then faced contender Conor McGregor losing by second round TKO.
Siver then fought Tatsuya Kawajiri losing by clear unanimous decision.
- Dennis Siver vs. Jonas Ericsson
- Dennis Siver vs. Adrian Degorski
- Arni Isaksson vs. Dennis Siver
- Dennis Siver vs. Jim Wallhead
- Jess Liaudin vs. Dennis Siver - The fight was Siver's UFC debut and Jess Liaudin's as well.
- Gray Maynard vs. Dennis Siver
- Melvin Guillard vs. Dennis Siver
- Dennis Siver vs. Nate Mohr - Siver ended the fight with another vicious spinning back kick.
- Dennis Siver vs. Dale Hartt - After the fight, Dale Hartt was cut.
- Dennis Siver vs. Paul Kelly
- Ross Pearson vs. Dennis Siver 1
- Dennis Siver vs. Andre Winner
- Dennis Siver vs. George Sotiropoulos
- Matt Wiman vs. Dennis Siver - The fight's unanimous decision result was controversial.
- Dennis Siver vs. Diego Nunes - The fight was the featherweight debut of Siver. Siver came in overweight. The decision declaring Siver the winner was considered controversial but it was undeniably a very close fight.
- Cub Swanson vs. Dennis Siver
- Dennis Siver vs. Charles Rosa - The fight was the UFC debut of undefeated late replacement Charles Rosa. The fight was Rosa's first loss.
- Conor McGregor vs. Dennis Siver
- Tatsuya Kawajiri vs. Dennis Siver