Casey is of Mexican descent.[3] A former Division I soccer player at the University of Texas at El Paso, Casey began training MMA in 2009 after her soccer career was cut short due to an injury. She began her amateur career in 2012, and her professional career a year later.
Mixed martial arts career
Amateur career
Casey made her amateur debut in 2012, losing a split decision to future UFC Strawweight Emily Kagan. Casey then went on a four fight win streak, earning three wins by armbar and capturing the Tuff-N-Uff Flyweight title in the process and defending it once.
Professional career
Early career
Casey made her professional debut in 2013 defeating Kelly Warren by rear naked choke.
Casey was then submitted by Pearl Gonzalez by armbar in her second fight.
After the loss Casey signed with the Middle Eastern promotion PXC before going on a three fight win streak, finishing all of her opponents.
Casey faced Cristina Stanciu at UFC Fight Night: McDonald vs. Lineker on July 13, 2016. She earned her first UFC win by defeating Stanciu by TKO in the first round.[6]
Casey next faced Randa Markos at UFC 202 on August 20, 2016.[7] Casey caught Markos in an armbar, to which she verbally submitted, giving Casey back-to-back UFC wins.[8]
Casey next faced Cláudia Gadelha at UFC Fight Night: Bader vs. Nogueira 2. She lost the fight by unanimous decision. During the third round there was controversy when Gadelha appeared to land an illegal head kick on Casey while Casey was grounded. However, the referee deemed the kick unintentional and no point was deducted. A replay showed that Gadelha's shin appeared not to hit Casey's skull but caught her hair instead. Casey was criticized for allegedly trying to play up the illegal head kick and possibly achieve a disqualification win.[9]
Casey next faced Jessica Aguilar at UFC 211 on May 13, 2017.[10] She won the fight via unanimous decision. However, the result of the fight was overturned to a No Contest and Casey was suspended for three months by the Texas Department of Licensing and Regulation after an in-competition sample provided by Casey was found to have an elevated testosterone to epi-testosterone ratio. Several experts questioned the findings [11][12] and in June 2017 she was exonerated by the UFC after follow up testing showed no evidence of doping.[13] On June 29 the UFC issued a strongly worded statement requesting that "the Texas Department of Licensing and Regulation (TDLR) immediately reverse its ruling and exonerate Cortney of any wrongdoing".[14] In turn, on June 30, the TDLR lifted Casey's three-month suspension and reinstated her victory.[15]
Casey was expected to face Priscila Cachoeira on October 31, 2020 at UFC Fight Night 181.[32] However the bout was called off the day of the weigh-ins as Cachoeira had issues cutting weight.[33]
Casey was expected to face Liana Jojua on August 21, 2021 at UFC on ESPN 29.[36] However, Jojua was forced out of the fight due to visa issues.[37] The matchup was rescheduled at UFC Fight Night 197 on November 13, 2021.[38] At the weigh-ins, Jojua weighed in at 128.5 pounds, two and a half pounds over the flyweight non-title fight limit. The bout proceeded at a catchweight with Jojua fined 30% of her purse, which went to her opponent Casey.[39] Casey won the bout via unanimous decision.[40]
Casey was scheduled to face Antonina Shevchenko on April 30, 2022 at UFC on ESPN 35.[41] However, the bout was postponed to July 9, 2022 at UFC on ESPN 39 due Shevchenko injured her knee in training.[42] Casey lost the fight via split decision.[43]
Casey was scheduled to face Jasmine Jasudavicius on February 25, 2023, at UFC Fight Night 220.[44] However, Casey withdrew from the event due to an undisclosed medical reason and was replaced by Gabriella Fernandes.[45]
On September 14, 2023, Casey had accepted a 4–month suspension by USADA after she reported herself in June 2023 for taking the prohibited substance BPC-157 to treat a medical condition. She is able to compete again as of October 1, 2023.[46] On September 19, 2023, it was reported that Casey was removed from UFC roster.[47]