Although Thuram-Ulien was born in
Courcouronnes, France, he spent most of his childhood in
Guadeloupe. He arrived at
Monaco in 2003. He was a part of Monaco's
2007–08 CFA squad that won the reserve's professional title. During the summer of 2008, he signed his first professional contract, keeping him with Monaco until 2011. He was given squad number 1 and designated as third keeper. He unexpectedly made his professional debut on 29 November 2008 in a 1–0 victory over
Auxerre coming on as a substitute in the 37th minute for the injured
Flavio Roma who was starting in place of the injured first-choice keeper
Stéphane Ruffier. Thuram kept a clean sheet for the rest of the match. Due to the severity of Roma's injury and Ruffier being out indefinitely as well, Yohann started the following week against
Sochaux. Yohann performed well enough for Monaco to earn a 1–1 draw. Before signing his professional contract with Monaco,
Barcelona showed interest in the young keeper. On 26 June 2010, Thuram signed a contract extension with Monaco until 2012. Four days later, he was loaned to second division club
Tours in order to get some consistent playing time. In the summer of 2013, he signed a contract with
Standard Liège. On 13 January 2014, Thuram-Ulien joined English club
Charlton Athletic on loan until the end of the season; he made four first-team appearances and kept one clean sheet. According to an article in the
Evening Standard, manager
Chris Powell was ordered to play Thuram-Ulien over
Ben Hamer by the club's owner
Roland Duchâtelet. On 2 August 2016, Thuram signed a three-year contract for French club
Le Havre. He signed for
Le Mans, newly promoted to Ligue 2, in July 2019. On 17 July 2020,
Amiens announced the signing of Thuram-Ulien on a two-year deal. On 2 August 2022, Thuram signed with
Quevilly-Rouen for one year. ==International career==