Early career After going the distance in her 2013 pro debut, she would go on to finish her next 10 bouts in the first round. In 2016, her one appearance came against Laisa Coimbra for the Aspera FC Bantamweight Championship. She won the title with an 87-second knockout — via a punch to the body. Taila set to fight with fellow Brazilian prospect
Mariana Morais, but Morais withdrew from the Aspera FC 32 bout. Being booked for her Invicta FC debut against
Irene Aldana, Santos had to pull out due to visa issues. After two year layoff, she was invited onto
Dana White's Contender Series Brazil 2 where she faced off at Flyweight against Estefani Almeida. She won the unanimous decision and earned a UFC contract.
Ultimate Fighting Championship Santos made her UFC debut against
Mara Romero Borella on February 2, 2019 at
UFC Fight Night: Assunção vs. Moraes 2. She lost the fight by split decision. Taila faced
Molly McCann on 16 July 2020 at
UFC on ESPN: Kattar vs. Ige. She won the fight via unanimous decision. Santos was scheduled to face
Maryna Moroz on December 5, 2020 at
UFC on ESPN: Hermansson vs. Vettori. However on November 18, it was announced that Moroz had to pull out and she was replaced by
Montana De La Rosa. Just hours before the event, the UFC decided to remove the fight after one of De La Rosa's cornermen tested positive for COVID-19. Santos was then rescheduled to face
Gillian Robertson two weeks later at
UFC Fight Night: Thompson vs. Neal. Santos won the fight via unanimous decision. Santos was scheduled to face
Roxanne Modafferi on May 8, 2021 at
UFC on ESPN 24. However, Modafferi was forced to pull out from the event citing a meniscus tear. Santos was scheduled to face Mandy Böhm on September 4, 2021 at
UFC Fight Night 191. However, Santos was pulled from the bout due to visa issues and was replaced by
Ariane Lipski. Santos faced
Roxanne Modafferi in a flyweight bout on September 25, 2021 at
UFC 266. She won the fight via unanimous decision. Santos faced
Joanne Wood on November 20, 2021 at
UFC Fight Night 198. After knocking Wood down twice, Santos won the bout via rear-naked choke at the end of the first round. This fight earned her the
Performance of the Night award. Santos faced
Valentina Shevchenko for the
UFC Women's Flyweight Championship on June 11, 2022, at
UFC 275. She lost the close bout by split decision, becoming the first fighter to win on a judge's scorecard against Shevchenko, in the flyweight division. Santos was scheduled to face
Erin Blanchfield on February 18, 2023 at
UFC Fight Night 219. The main event fight between
Cory Sandhagen and
Marlon Vera was rescheduled to another event, and Santos' fight against Blanchfield was promoted to the main event. However, just one week out from the event, Santos withdrew after her cornermen were denied visas into the United States and was replaced by former
UFC Women's Strawweight Champion Jéssica Andrade. The match with
Erin Blanchfield was rebooked and took place on August 26, 2023, at
UFC Fight Night 225. She lost the bout via unanimous decision. On November 7, 2023, it was announced that Santos was no longer under contract with the UFC.
Professional Fighters League On March 1, 2024, it was reported that Santos signed with
Professional Fighters League. Santos was scheduled to make her debut against
Denise Kielholtz on April 4, 2024 at
PFL 1. However, a week before the event it was announced that Kielholtz had pulled out and she would instead face llara Joanne. Santos won the bout by a rear-naked choke submission at the end of the first round. Santos faced Jena Bishop at
PFL 4 on June 13, 2024. She won the bout via split decision. Santos faced
Liz Carmouche in the semi-finals of the
2024 Women's Flyweight tournament at
PFL 7 on August 2, 2024. At the weigh-ins, Carmouche missed weight by 1 pound, coming in at 127 pounds. Santos won the bout via unanimous decision. In the final, Santos faced
Dakota Ditcheva on November 29, 2024, at
PFL 10. ==Championships and accomplishments==