That was the greatest performance I have ever seen in my life!… You surpassed all expectations tonight with this performance. This was just … stunning…. This was incredible…. T.J., this is one of the finest performances I have ever seen. The best performance — I’ll say it right now — this is the most spectacular performance I have ever seen against a guy in Barão who is easily one of the best pound-for-pound fighters on the planet. Congratulations on just a masterful work tonight. It was an honor calling this fight. Thank you very much, brother.
Dillashaw was born in Sonora, California, to Hal and Janice Dillashaw. He grew up in Angels Camp, California, where he also attended Bret Harte High School. During his four years there, Dillashaw competed on the school's wrestling team and played on the football team for his 2002-2003 junior year. In June 2004 he graduated and enrolled for college at California State University, Fullerton. At college, Dillashaw competed successfully for the Titans wrestling program.
With a successful high school career, Dillashaw received a full-ride scholarship to wrestle for Cal State Fullerton Titans. In the 2005–06 season, Dillashaw's freshman year, he posted a 14–16 record including a 10–8 mark in dual matches. He went 3–4 in Pac-10 dual meets. Dillashaw traveled to Ukraine in the summer of 2006 to work on his wrestling skills. Dillashaw's sophomore season was a more successful one having an overall record of 17–14 with an 11–4 mark in duals, including 5–3 in the Pac-10. In April 2007, he placed sixth in the University Greco Wrestling Championships in Akron, Ohio, at 132.25 pounds. He also placed fourth at the Pac-10 championship in 2007.
In 2008, he placed fourth in the Pac-10 Championships and finished with a 22–10 record with four pins. He was 7–0 in Pac-10 duals, taking second place at Cliff Keen Invitational. His senior season he was ranked 10th in the nation at 133 lbs. Dillashaw is a 3X NCAA qualifier.
On March 26, 2010, Dillashaw made his professional debut against fellow pro debutee, Czar Sklavos. Dillashaw used his superior wrestling to earn a dominant unanimous decision win. Two months later, Dillashaw returned to fight Brandon Drucker, winning the fight via first round submission. The fight took place at Fight For Wrestling, an MMA event located in California attempting to raise money to fund the Cal Poly wrestling team.
Dillashaw officially made his UFC debut on December 3, 2011, in Las Vegas, Nevada at The Ultimate Fighter 14 Finale. The fight was the final of the bantamweight tournament against John Dodson to determine the winner of The Ultimate Fighter 14. Dillashaw lost via TKO.
Dillashaw was expected to face Mike Easton on December 8, 2012, at UFC on Fox 5. However, Dillashaw was forced out of the bout with an injury and replaced by Bryan Caraway.
The bout with Assunção was rescheduled and took place on October 9, 2013, at UFC Fight Night 29. Assunção defeated Dillashaw via split decision. The back and forth action earned both the participants Fight of the Night honors.
An immediate rematch with Barão was scheduled to take place on August 30, 2014, at UFC 177. However, the day of the weigh-ins, Barão had to be admitted to the hospital as a result of his attempts to cut weight and was replaced by Joe Soto who was already scheduled to compete in a fight on the event's preliminary card. Dillashaw defeated Soto via knockout in the fifth round. The win also earned Dillashaw his second consecutive Performance of the Night bonus award.
The rematch eventually took place at UFC on Fox 16 on July 25, 2015. Dillashaw won the fight via TKO in the fourth round to retain his title. He also earned a Performance of the Night bonus.
Dillashaw faced John Lineker on December 30, 2016 at UFC 207. He won via a dominant unanimous decision, wherein the bout was scored a 30-26 in favour of Dillashaw by all three judges.
Dillashaw married his wife, Rebecca, in June 2014. In October 2015, Dillashaw left Team Alpha Male and moved his camp to Denver, Colorado to train with his head coach, former UFC fighter Duane Ludwig. On December 28, 2017, Dillashaw’s wife Rebecca gave birth to their son.
Dillashaw is schedule to faced Cody Garbrandt on a rematch for the UFC Bantamweight Championship on August 4, 2018 at UFC 227.