The sixteen participating national teams were required to submit squads of 18 players – of which two have to be goalkeepers – by 30 June 2021, 23 days prior to the opening match of the tournament.
The numbers of caps and goals listed for each player do not include any matches played after the start of the tournament.
[5] Before the start of the tournament, Niels Nkounkou was called up to replace the injured Jérémy Gelin.
[8] Head coach: Hajime Moriyasu * Overage player Mexico's 22-man final squad was announced on 15 June 2021.
[9] On July 4, José Juan Macías withdrew due to injury and was replaced by Adrián Mora.
[16] On 9 July, Dragoș Nedelcu, who was set to complete a loan move to Fortuna Düsseldorf, withdrew from the squad at the request of the club and replaced by Ronaldo Deaconu.
[25] The 22-man squad was announced on 29 June 2021,[26][27] with Iván Villar replacing the injured Álex Domínguez.
[28] Head coach: Luis de la Fuente * Overage player.
[31] On 8 July, Ricardo Graça replaced Gabriel Magalhães who withdrew injured.
[32] On 14 July, Malcom replaced Douglas Augusto who withdrew injured.
[34] Ragnar Ache and Keven Schlotterbeck were nominated five days later, after Josha Vagnoman and Niklas Dorsch withdrew.
[38] Turki Al-Ammar withdrew injured and was replaced by Firas Al-Buraikan on 21 July.