Taleb began his professional career with a unanimous decision victory, before losing his next bout via TKO. After a further four victories across Canada, Taleb fought Pete Sell at Ring of Combat 38 for Sell's welterweight championship. Taleb was the much quicker man and was able to move in and out of range quickly, which reduced the amount of strikes he took from Sell. In the second round, Taleb hit Sell with a counter right hand, followed by strikes on the ground. The referee stopped the fight early in the second round and Taleb was declared the ROC Welterweight Champion.
In 2011, Taleb was signed by Bellator and made his debut at Bellator 64 against Matt Secor. Taleb dominated the fight and outclassed Secor enough to be awarded 10-8 rounds by one judge. Taleb was able to take Secor down multiple times and also controlled the stand-up portion of the fight. Taleb won via unanimous decision. Taleb's second fight for Bellator was against Matt MacGrath, which was held as a 180lb. Catchweight bout, due to the fight being contested at short notice. Taleb controlled MacGrath in the opening round, by utilising his reach advantage via straight punches. MacGrath started to come back into the fight in the second round, but was knocked down by a left hand from Taleb. Taleb hit MacGrath with some follow-up shots and was declared the winner via TKO. Taleb was then entered into the. Taleb's opponent in the quarterfinal was the first-and-only DREAMwelterweight championMarius Žaromskis. Taleb lost via unanimous decision.
The Ultimate Fighter
In December 2013, it was announced that Taleb was selected as one of the fighters to represent Canada for the upcoming. In his first fight on the show, Taleb lost to Tyler Manawaroa via unanimous decision after three rounds. In a rare move, the UFC revealed in March 2014 that Taleb would also appear as a participant on the next season of the show,. Taleb lost his preliminary fight to get into the house against Mike King via decision after a sudden victory round.
Ultimate Fighting Championship
Despite being announced as a participant on, Taleb appeared on the event leading up to its premiere as he faced fellow contestant Vik Grujic at. He won the bout via unanimous decision. Taleb faced Li Jingliang on October 4, 2014 at. He won the fight via split decision and marked a successful return to welterweight. Taleb was expected to face Cláudio Silva on April 25, 2015 at UFC 186. However, Silva was forced out of the bout with a broken foot and replaced by Chris Clements. Taleb won the fight by unanimous decision. Taleb faced Warlley Alves on August 1, 2015 at UFC 190. He lost the fight by submission in the second round. Taleb faced Erick Silva on March 5, 2016 at UFC 196. He won the fight via knockout in the second round. Taleb was expected to face Alan Jouban on July 7, 2016 at UFC Fight Night 90. However, Taleb pulled out of the bout in early June citing an injury. Taleb faced Santiago Ponzinibbio on February 19, 2017 at UFC Fight Night 105. He lost the fight by unanimous decision. Taleb was expected to face Emil Weber Meek on 28 May 2017 at UFC Fight Night 109. However, Meek pulled out of the fight on May 12 citing injury. Meek was replaced by promotional newcomer Oliver Enkamp. He won the fight by unanimous decision. Taleb was expected to face Sultan Aliev on 16 December 2017 at. However, Aliev was removed from the card for undisclosed reasons in early December and was replaced by Danny Roberts. Taleb won the last bout of his contract by knockout in the first round. This win earned him the Performance of the Night bonus. Taleb faced Cláudio Silva on 27 May 2018 at UFC Fight Night 130. He lost the fight via a rear-naked choke in the first round. Taleb faced Sean Strickland on 27 October 2018 at UFC Fight Night 138. He lost the fight via technical knockout in the second round. Taleb was scheduled to face Siyar Bahadurzada on 4 May 2019 at. However, it was reported on April 24, 2019 that Bahadurzada pulled out of the bout citing injury, and he is replaced by newcomer Kyle Prepolec. Taleb won the fight via unanimous decision. Taleb faced Muslim Salikhov on September 7, 2019 at UFC 242. He lost the fight via knockout in round one.
Post-UFC career
After parting ways with the UFC, Taleb was expected to headline ARES 2 on April 3, 2020, against Maarten Wouters. However, due to the COVID-19 pandemic, the event was postponed until October 30, 2020.
