|Full name||Nicolas Alexis Julio Nkoulou Ndoubena|
|Date of birth||27 March 1990|
|Place of birth||Yaoundé, Cameroon|
|Height||5 ft 11 in (1.80 m)|
|Kadji Sports Academy|
* Senior club appearances and goals counted for the domestic league only and correct as of 20 July 2015.
Nkoulou began his career at Kadji Sports Academy in Douala. The same academy that produced the likes of Samuel Eto'o, Carlos Kameni, and Eric Djemba-Djemba. In late 2007, it was announced that he was acquired by the principality-based side AS Monaco FC. He agreed to a three-year professional contract. He spent the latter portion of the 2007–08 season playing with Monaco's CFA squad, before joining the squad for preseason in July 2008, where he was handed the number 3 kit.
He made two appearances during the pre-season starting their opening friendly match against fellow Ligue 1 side Toulouse FC and also starting against Croatian side NK Zagreb. He made his professional debut on 13 September 2008 in a 2–0 victory over FC Lorient starting the match before being substituted in the 65th minute. He has started every match since playing the full 90 minutes in them all. He has yet to score a goal.
His performances with Monaco have led to him being scouted by several prominent European clubs. English clubs Arsenal and Hull City, Spanish sides Sevilla and Atlético Madrid, and French champions Olympique Lyonnais have all declared their interests in the Cameroonian defender. On 29 June 2011, N'Koulou passed his medical and signed for four years with Marseille.
N'Koulou was included in the Cameroon U-23 squad that participated in the 2008 Summer Olympics. He helped the squad reach the knockout round, where they were eliminated by Brazil. He would make his international debut in the senior squad on 19 November 2008 in a friendly against South Africa.
Individual Ligue 1 Team of the Year (2): 2012,2013