Didier Ibrahim Ndong (born 17 June 1994) is a Gabonese professional footballer who plays as a midfielder for Persian Gulf Pro League side Esteghlal and the Gabon national team.

Sunderland were relegated to EFL League One at the end of the 2017–18 season and a number of high-profile players, including Ndong, expressed their desire to leave the club rather than play in England's third tier.

Sunderland fans' feelings toward the club's record signing became increasingly hostile, made worse when Ndong appeared to post an image on Instagram of him sitting poolside at a holiday resort.

[20] The parallels with the Ndong situation were noted at the time of Djilobodji's sacking, with public comments from Stewart Donald suggesting that the players were "deliberately devaluing themselves" in order to engineer cheaper moves away from the club.

On 21 September, Ndong reportedly issued a statement via representatives that he had been spending time in Morocco, but wished to return to Sunderland to fight for his place in the team.

The player, who was under contract with the club until June 2021, failed to return to Sunderland for pre-season training in July as scheduled, nor in the subsequent months that followed.

Sunderland AFC does so whilst retaining the right to pursue the player and any club he may subsequently join in relation to compensation for the value of the player.Following his sacking, Ndong had to leave the United Kingdom due to his residence permit expiring.

He returned to Gabon and began training with an unnamed club in Libreville in October 2018, amid reports of personal financial difficulties.

[25] On 11 October 2018, Sunderland released a statement on their website indicating that an amicable agreement had been reached and Ndong was no longer an employee of the club.

[26] On 28 December 2018, En Avant Guingamp announced that they were due to sign Ndong, following medical exams and finalising a deal with Sunderland.

[32] In 2013, Anicet Yala, coach of the Gabon national U20 team, called him up to be a member of the squad for the 2013 African Youth Championship in Algeria.