The following is a list of squads for each nation competing at the 2009 World Baseball Classic. The tournament started on March 5, 2009.
Each participating national federation had a deadline of January 19, 2009 to submit a 45-man provisional roster. Final rosters of 28 players, which also must include a minimum of 13 pitchers and two catchers, were submitted on February 24. If a player on the submitted roster is unable to play, usually due to injury, he can be substituted at any time before the start of the tournament. Roster changes during the competition are restricted to the breaks between rounds of competition—for example, a player who is injured during pool play could not be replaced during the pool phase, but could be replaced if his team advanced to the second round.
Team affiliations on all rosters, and player ages, are current as of the opening day of the tournament.
Manager: 77 Terry Collins
Coaches: 66 Brent Strom, 72 Aiping Wang, 29 Sheng Yi
Manager: 3 Chih-Hsien Yeh (葉志仙)
Coaches: 88 Tai-Yuan Kuo (郭泰源), 26 Kong-Hui Wang (王光輝), 70 Wen-Sheng Lu (呂文生), 6 Chen Wei-Cheng (陳威成), 65 Lin Kun-Han (林琨瀚), 68 Cheng-Hao Wang