Clay Guida (/ˈɡwiːdə/; born December 8, 1981) is an American professional mixed martial artist, who competed in the UFC in the Lightweight division.

A professional competitor since 2003, Guida also formerly competed for Strikeforce, the WEC, King of the Cage, and Shooto.

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.

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 2006.

[13] Guida garnered attention for his three-round split decision loss to Tyson Griffin at UFC 72.

[15] At UFC 74 Guida rebounded from his two consecutive losses, taking a split decision over PRIDE veteran Marcus Aurélio.

[18] In a bout at UFC Fight Night 15, he defeated Mac Danzig via unanimous decision (30–27, 29–28, 29–28).

[19] Guida defeated Ultimate Fighter winner Nate Diaz via split decision at UFC 94.

In the second round of a bloody fight, Guida was dropped by a right hand and lost via rear-naked choke.

[30] At UFC Live: Vera vs. Jones Guida defeated Shannon Gugerty at 3:40 of round 2 by way of arm-triangle choke,[31] ending Guida's two fight losing streak along with winning his first UFC Submission of the Night award.

[36] 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.

[42] 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.

[47] 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.

[58] Guida next faced Erik Koch at UFC Fight Night: Chiesa vs. Lee on June 25, 2017.

[60] Guida faced Joe Lauzon on November 11, 2017, at UFC Fight Night: Poirier vs. Pettis.

[62] However, Green pulled out of the bout, citing an injury and was replaced by Charles Oliveira[63] Guida lost the fight via guillotine choke submission in the first round.

[66] On June 28, 2019, it was announced that the fight between Guida and Diego Sanchez at The Ultimate Fighter 9 Finale, where Sanchez defeat Guida by split decision, on June 20, 2009, will be honored to enter the UFC Hall of Fame during the international fight July 2019.

[68] He lost the fight via a technical submission due to a guillotine choke in the first minute of the first round.

[69] Guida faced Bobby Green on June 20, 2020, at UFC Fight Night: Blaydes vs.

[76] Guida faced Leonardo Santos on December 4, 2021, at UFC on ESPN: Font vs.

[91] Guida returned to wrestling competition at the 2022 US Open, competing alongside his teammate Urijah Faber at the event.