Originally from Cottage Grove, Minnesota, O'Connell competed in football and wrestling at Jordan High School in Sandy, Utah before continuing his football career collegiately. While in high school O'Connell was a member of the coveted football group Pain Train, which was reserved for only the toughest members of the offensive line. However, O'Connell would transfer to three different schools including Southern Utah University and The University of Utah where he made the team as a walk-on, while looking to get more playing time. O'Connell eventually lost interest and turned his attention to mixed martial arts. O'Connell graduated from The University of Utah, with a degree in psychology. He also attended Weber State.
O'Connell made his professional MMA debut in 2007 with no previous training other than cardio kickboxing which he would do to help stay in shape. Despite having limited training, O'Connell was successful early on in his career and held an overall record of 6-2, which earned him an invitation to compete on. O'Connell, however, was eliminated in the opening round to make it to the final cast. O'Connell, who also ran a talk show for a radio station in San Francisco at the time, was on a five-fight winning streak and held an overall professional record of 14-4, before inviting UFC president Dana White to come onto his show. O'Connell asked White for a contract and was signed a year later. O'Connell was the co-host of a popular sports talk radio show on ESPN700 in Utah called The OC and Hackett Show
Ultimate Fighting Championship
O'Connell made his promotional debut as a short notice injury replacement at on April 16, 2014 against Ryan Jimmo. O'Connell was defeated via knockout in the first round. His next appearance was also a short notice fight against Gian Villante on June 28, 2014 at UFC Fight Night 43, where he replaced an injured Anthony Perosh. O'Connell lost the fight via split decision. Their performance earned both participants Fight of the Night honors. On January 18, 2015, O'Connell then faced Matt Van Buren at UFC Fight Night 59.; he won via third-round TKO. Both participants earned Fight of the Night honors. He then faced Anthony Perosh on May 10, 2015 at UFC Fight Night 65. He won the fight via TKO in the first round. O'Connell has been known to goof around during weigh-ins before the fight, such as booping Van Buren on the nose or playing an improvised game of rock-paper-scissors with Perosh. He claims he does his jokes to add levity to an otherwise tense situation. O'Connell faced Ilir Latifi on January 17, 2016 at UFC Fight Night 81. He lost the fight by knockout in the first round. O'Connell next faced Steve Bossé on June 18, 2016 at UFC Fight Night 89. Bossé was awarded a unanimous decision victory. The back and forth action earned both participants Fight of the Night honors. O'Connell faced Corey Anderson on December 9, 2016 at UFC Fight Night 102. He lost the fight by TKO in the second round.
Professional Fighters League
O'Connell signed with PFL in 2018. In his debut, he faced Ronny Markes at PFL 2 on June 21, 2018 in Chicago, Illinois, winning the fight by TKO in the second round. In his second fight for the promotion, O'Connell faced Bazigit Atajev at PFL 7 on August 30, 2018. He lost the fight via TKO in the first round. In the fall of 2018, O'Connell entered the PFL Light Heavyweight tournament. At PFL 9 on October 13, 2018, he defeated Dan Spohn by majority decision in the quarterfinal round and then fought Smealinho Rama in the semifinal round the same night, winning by knockout. O'Connell faced Vinny Magalhães in the finals at PFL 11 on December 31, 2018. He won the back-and-forth fight via TKO between the third and fourth round after Vinny Magalhães stopped the bout. With the win, O'Connell was crowned the 2018 PFL Light Heavyweight champion and earned the $1 million cash prize.
Retirement
Following his PFL tournament win, O'Connell announced he was retiring from MMA competition.
