This article shows the 12-player roster of all participating teams at the 2023 FIVB Volleyball Men's U21 World Championship.
Pool A Bahrain A 12-player squad was announced on 6 July 2023.
Head coach: Saber Abdulwahed
Iran A 12-player squad was announced on 6 July 2023.
Head coach: Gholamreza Momeni Moghaddam
Thailand A 12-player squad was announced on 4 July 2023.
Head coach: Kampol Sripo
Tunisia A 12-player squad was announced on 6 July 2023.
Head coach: Hosni Karamosly
Pool B Brazil A 12-player squad was announced on 5 July 2023.
Head coach: Guilherme Novaes
Egypt A 12-player squad was announced on 5 July 2023.
Head coach: Hani Moselhi
Italy A 12-player squad was announced on 4 July 2023.
Head coach: Matteo Battocchio
Mexico A 12-player squad was announced on 7 July 2023.
Head coach: Jorge Romero
Pool C Bulgaria A 12-player squad was announced on 4 July 2023.
Head coach: Andrea Burattini
Canada A 12-player squad was announced on 6 July 2023.
Head coach: Arnd Ludwig
India A 12-player squad was announced on 6 July 2023.
Head coach: G. E. Sridharan
Poland A 12-player squad was announced on 3 July 2023.
Head coach: Mateusz Grabda
Pool D Argentina A 12-player squad was announced on 4 July 2023.
Head coach: Sebastián Fernández
Belgium A 12-player squad was announced on 6 July 2023.
Head coach: Michel Mariën
Czech Republic A 12-player squad was announced on 5 July 2023.
Head coach: Jan Svoboda
United States A 12-player squad was announced on 30 June 2023.
Head coach: Andy Read
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