With twelve victories record without a defeat, Till drew the attention of the world’s largest fighting organization Ultimate Fighting Championship and in May 2015 made his successful debut. He came out on a short notice against the Brazilian Wendel de Oliveira (learned about the fight just nine days before his beginning) and knocked him out in the second round.
In October 2015 Till went against the Dane Nicolas Dahlby. The opposition between them lasted all the time allotted, as a result, the decision of the majority of judges was a draw. Both fighters were awarded “The Best Fight of The Evening” award.
Because of shoulder injury and various personal circumstances, Till had not fought with anyone for a long time. Finally, in May 2017, he faught with a little-known German of Tunisian origin, Yessin Ayari. The English fighter did not meet the welterweight limit, showing an excess of about five pounds, and was forced to give 20% of his fee in favor of the opponent. He explained the failure of weighing by saying that he had no fights for a long time, and that his body did not respond to the striking as it did before. With all that, he confidently surpassed Aiari on points and won by unanimous decision of the judges.
In August 2017, Till signed a new contract with the UFC for five fights, and then overcame such well-known fighters as Boyan Velichkovic and Donald Cerronet, in the fight against the latter he received a bonus for the best performance of the evening.
In May 2018 at the home tournament in Liverpool in the main event of the evening, Darren Till met with American Stephen Thompson, the highest rated fighter of the WFC welterweight. He again did not meet the weight constraint, exceeding the limit by three and a half pounds. After negotiations with the team of Thompson, the fight was decided to be held in intermediate weight, tho on the day of the fight Till should have not weighted more than 85.3 kg. In addition 30% of the fee was transferred to the American fighter. Till coped with the established requirement, even tho the weight race was very hard for him. As a result, the fight lasted all five rounds, and the judges unanimously decided to give Till the win. The decision turned out to be very controversial. 22 out of 25 experts recognized Thompson as the winner in this battle. Anyway, the victory over Stephen Thompson allowed Till to rise to the second place of the middleweight UFC rating.