He is one of the most experienced fighters in the sport of mixed martial arts, with a professional record of 84–19–5, with a total of 108 fights. His last stint in the UFC was ended with a three-fight losing streak to Nate Marquardt, Dean Lister and Rousimar Palhares.
He most recently defeated fellow UFC veteran Sean Salmon and then Brian Warren, in his fifth and sixth straight wins since leaving the UFC. He most recently fought September 28th in Bellator in his promotional debut against Bryan Baker, losing via decision. He was next set to fight October 29th in KOTC against Jake Rosholt but instead Rosholt was changed to face Matt Horwich.
He next faced Lee McKibbin in Ireland, winning via guillotine choke. He moved on to clash with UFC veteran Thales Leites for the vacant Superior Challenge middleweight championship. Leites defeated Horn via split decision.
He next faced Shawn Marchand for the vacant Elite 1 MMA light-heavyweight title winning via first round rear-naked choke submission before then defeating Brad Scholten via another first round rear-naked choke submission.
Horn didn't fight for over two years after the Scholten fight before signing in January 2014 to return against Dan McGlasson.
- Jeremy Horn vs. Rick Graveson - The fight was Horn's MMA debut.
- Jeremy Horn vs. Mike Adsit
- Jeremy Horn vs. Daiju Takase - The fight was Daiju Takase's UFC debut and his first loss in his mixed martial arts career.
- Jeremy Horn vs. Adam Harris
- Jeremy Horn vs. Jason Godsey
- Jeremy Horn vs. Nate Parmelee
- Jeremy Horn vs. Jason Allar
- Jeremy Horn vs. Elvis Sinosic - The fight was Elvis Sinosic's UFC debut. The fight was considered an upset with the victory for Sinosic.
- Jeremy Horn vs. Ricardo Arona 2 - The fight was for Rings.
- Jeremy Horn vs. Dan Theodore
- Gilbert Yvel vs. Jeremy Horn
- Jeremy Horn vs. Aaron Brink
- Jeremy Horn vs. Forrest Griffin - The fight was in the semifinals of the IFC light-heavyweight tournament.
- Jeremy Horn vs. Dean Lister 1 - The fight was for the King of the Cage light-heavyweight title with Horn defending.
- Anderson Silva vs. Jeremy Horn
- Jeremy Horn vs. Chael Sonnen 2
- Jeremy Horn vs. Kazuki Okubo
- Jeremy Horn vs. Josh Burkman
- Chuck Liddell vs. Jeremy Horn 2 - The fight was the rematch, for the UFC light-heavyweight title with Chuck Liddell defending, his first title defense after winning the belt from Randy Couture.
- Jeremy Horn vs. Jorge Santiago - The fight was amazingly Horn's one hundredth fight.
- Jeremy Horn vs. Dean Lister 2
- Jeremy Horn vs. Rousimar Palhares - After the fight, Horn was cut from the UFC once more. Rousimar Palhares broke his hand sometime during the first round of the fight.
- Jeremy Horn vs. Brian Warren - Brian Warren came into the fight with a 13-14 record.
- Bryan Baker vs. Jeremy Horn - The fight was Horn's Bellator debut.
- Thales Leites vs. Jeremy Horn