In the Valenciennes academy, Ndiaye played alongside Dayot Upamecano, a player to whom he remained close to throughout his career. It was at the same time as the latter that he left Valencienne in 2016, who were in financial turmoil.[1][3] While Upamecano left for RB Leipzig, Ndiaye joined Auxerre, where he only played for a few months before joining Italian club Bologna. At the Serie A club, he played with the U19s and also practices with the first team under the leadership of Roberto Donadoni.[1][3] Ndiaye later stated, that he became the victim of player agents wanting to turn his development into profit, instead of focusing on naturally growing his talent. It was in this light that he joined Bari in Serie B.[1][3]
Lorca Deportiva
Having changed agents after his difficult stint in Italy, Ndiaye moved to Segunda División B club Lorca Deportiva in 2017, where he would go on to make his senior debut.[1][3] He put in several good performances during his first season, mainly as a defensive midfielder.[1][4]
Ndiaye scored his first senior goal on 5 November 2017 in a match against San Fernando — a spectacular strike from outside the box.[5] However, Lorca would end up suffering relegation to the fourth division.[6] At the end of the season, he terminated his contract by mutual consent.[1]
Suddenly a free agent, Ndiaye suffered a metatarsal injury that put his career on hold for more than nine months.[1]
Vorskla Poltava
In the summer of 2019, Ndiaye went on a trial with Ukrainian club Vorskla Poltava, where he was signed.[1][3] He would flourish in the Ukrainian Premier League, especially from 2020, where he establishes himself as a mainstay at centre-back. Most notably, he would perform well in a victory against champions Shakhtar Donetsk, inflicting their only defeat of the season.[7]
During the 2020–21 season, Ndiaye continued in great form and attracted the interest of several foreign clubs, including as West Ham United, Lille, Braga and Beşiktaş.[8][9]
He was also awarded the title of best defender of the first half of the season, where Vorskla were among the best teams in the league behind Shakhtar and Dynamo Kyiv, while his contract would expire in the summer of 2021.[10]
In July 2023, Ndiaye joined Turkish TFF First League club Şanlıurfaspor.[13] He made his debut for the club on 14 August, starting in a 2–1 league victory against Altay.[14]
Tobol
On 3 February 2024, Ndiaye signed with Tobol in Kazakhstan.[15]
^"DH : Moulaye N'Diaye assure le spectacle au FC". Paris-Normandie [fr] (in French). Retrieved 23 April 2021. Sur le chemin d'un avenir pro, celui qui aurait pu, plus jeune, rejoindre les centres de formation de Toulouse, Lille, Valenciennes ou Dijon, a deux exemples à suivre : son... petit frère Pape Alioune (15 ans), membre des U16 du VA FC.