Born and raised in Illinois into an Italian family, Guida began wrestling at the age of five and was a three-sport athlete at Johnsburg High School. He continued his wrestling career for NJCAA Harper College, where he won a national championship in 2001 and competed at 149 lbs.
Guida made his professional debut in the summer of 2003, losing via rear-naked choke in the first round. After compiling a record of 3-3, he then won his next 15 consecutive fights before losing via submission at a King of the Cage event in February of 2006. Guida was then signed by Strikeforce and fought a month later against Josh Thomson for the Strikeforce Lightweight Championship. Guida won via unanimous decision, before losing to the then-undefeated Gilbert Melendez. After losing his next bout overseas in Japan via submission, Guida was signed by Zuffa and the WEC, making his promotional debut at WEC 23. He won via unanimous decision. With an overall record of 20-6, Guida was signed by the UFC.
Guida was successful in his UFC debut, submitting Justin James in the second round at UFC 64.
Guida lost a unanimous decision to Din Thomas at UFC Fight Night: Evans vs. Salmon in his second UFC outing.
Guida garnered attention for his three-round split decision loss to Tyson Griffin at UFC 72.
At UFC 74 Guida rebounded from his two consecutive losses, taking a split decision over PRIDE veteran Marcus Aurélio.
Guida was defeated by Roger Huerta at The Ultimate Fighter 6 Finale via rear-naked choke in the 3rd round after clearly winning the first 2 rounds.
Guida returned to his winning ways at UFC Fight Night 13, where he defeated UFC newcomer Samy Schiavo via TKO at 4:15 of the first round.
In a bout at UFC Fight Night 15, he defeated Mac Danzig via unanimous decision (30-27, 29-28, 29-28).
Guida defeated Ultimate Fighter winner Nate Diaz via split decision at UFC 94.
His next fight was against Diego Sanchez, at The Ultimate Fighter: United States vs. United Kingdom Finale which he lost by split decision. The fight had a frantic pace in which Guida weathered a ferocious striking offensive from Sanchez, with a seemingly endless barrage of punches and a brutal headkick which dropped Guida in the first round. This bout went on to win Fight of the Night honors. The fight would later make #13 on the "100 Greatest UFC fights" list.
Despite his status as an up-and-coming UFC fighter he was not included in the UFC 2009 Undisputed video game due to technical issues caused by his long hair. He was even offered $10,000 by Dana White to cut it, but he refused.
On December 12, 2009 he fought Kenny Florian at UFC 107. In the second round of a bloody fight, Guida was dropped by a right hand and lost via rear-naked choke.
Guida was expected to face Sean Sherk on March 21, 2010 at UFC LIVE: Vera vs. Jones, but Sherk was forced off the card with an injury. Shannon Gugerty stepped up to become Guida's new opponent on the preliminary section of the event. At UFC Live: Vera vs. Jones Guida defeated Shannon Gugerty at 3:40 of round 2 by way of arm-triangle choke, ending Guida's two fight losing streak along with winning his first UFC Submission of the Night award.
Guida then faced Rafael dos Anjos on August 7, 2010 at UFC 117. Guida appeared to injure the jaw of dos Anjos in the first round with a hook and would go on to defeat dos Anjos by submission (jaw injury) after dos Anjos tapped from the pressure being applied to his jaw while Guida had head-and-arm control.
Guida defeated Takanori Gomi on January 1, 2011 at UFC 125 by submission due to a guillotine choke in round two, his third consecutive submission victory which also earned him Submission of the Night honors.
Guida next defeated former #1 Lightweight contender Anthony Pettis via unanimous decision (30-27, 30-27, 30-27) on June 4, 2011 at The Ultimate Fighter 13 Finale.
Guida faced Benson Henderson on November 12, 2011 at UFC on Fox 1. Guida lost a hard fought decision after three rounds.
Guida faced Gray Maynard on June 22, 2012 at UFC on FX 4. Guida lost to Maynard via split decision. During the post-fight press conference, Guida drew much criticism for his non-combatant, elusive and frustrating game plan. When asked by reporters how he thought he did, Guida said he was "happy with his performance". Dana White wholeheartedly disagreed, calling the fight "boring" and said "the fight sucked". White also told Guida that his UFC career is over if he continues to fight in such a manner.
For his next fight, Guida moved down to the featherweight division and faced Hatsu Hioki on January 26, 2013 at UFC on Fox: Johnson vs. Dodson. Despite being outstruck by Hioki for the majority of the fight, Guida was able to take Hioki down multiple times using a strong top game and avoid Hioki's submission attempts from the bottom. Guida defeated Hioki via split decision.
Guida was expected to face Chad Mendes on April 20, 2013 at UFC on Fox 7. However it was revealed on March 15 that Guida had pulled out of the bout citing an injury.
A rescheduled bout with Mendes took place on August 31, 2013 at UFC 164. After a close first and second round, Guida was defeated by Mendes via TKO by punches, marking the first time ever in his career that he was finished by strikes.
Guida faced Tatsuya Kawajiri at UFC Fight Night 39. He won the fight by unanimous decision, in a performance that earned both participants Fight of the Night honors.
Guida faced Dennis Bermudez on July 26, 2014 at UFC on Fox 12. He lost the bout via submission in the second round.
Guida faced Robbie Peralta on April 4, 2015 at UFC Fight Night 63. He won the fight by unanimous decision.
Guida faced Thiago Tavares on November 7, 2015 at UFC Fight Night 77. He lost the fight due to a guillotine choke submission early in the first round.
Guida faced Brian Ortega on June 4, 2016 at UFC 199. He lost the fight via KO in the third round.
Guida next faced Erik Koch at UFC Fight Night: Chiesa vs. Lee on June 25, 2017. He won the fight by unanimous decision.
Guida is expected to face Joe Lauzon on November 11, 2017 at UFC Fight Night 120.
Clay Guida starred in a National commercial for SafeAuto Insurance. The commercial was filmed in Columbus, Ohio in April 2011. Guida is one of several fighters who represents the SafeAuto Fight Team.
Guida is managed by VFD Sports Marketing, a sports marketing company that focuses on UFC athletes.Strikeforce
Strikeforce Lightweight Championship (One time; first)
Ultimate Fighting Championship
Fight of the Night (Six times)
Submission of the Night (Three times)
Fight of the Year vs. Roger Huerta (2007)
World MMA Awards
Fight of the Year vs. Diego Sanchez (2009)
Wrestling Observer Newsletter
Fight of the Year (2009) vs. Diego Sanchez on June 20
Tequila CAZADORES Spirit Award
Tequila CAZADORES Spirit Award (Two times)--
Guida is a fan of the Chicago Bears. Guida is also a die hard Grateful Dead fan. He attended the GD50 Grateful Dead reunion shows.