U（28）
- Active Players
- U
U
- 69 Pitcher
- Uchi, Seiryu
- Tohoku Rakuten Golden Eagles
- 63 Infielder
- Uchida, Shodai
- Hiroshima Toyo Carp
- 161 Pitcher (*)
- Uchino, Kaito
- Fukuoka SoftBank Hawks
- 33 Catcher
- Uchiyama, Souma
- Tokyo Yakult Swallows
- 14 Pitcher
- Udagawa, Yuki
- ORIX Buffaloes
- 51 Outfielder
- Uebayashi, Seiji
- Chunichi Dragons
- 62 Infielder
- Ueda, Kai
- Hanshin Tigers
- 10 Infielder
- Ueda, Kyuto
- Chiba Lotte Marines
- 45 Catcher
- Ueda, Shota
- Chiba Lotte Marines
- 11 Pitcher
- Ueda, Taiga
- Saitama Seibu Lions
- 20 Pitcher
- Uehara, Kenta
- Hokkaido Nippon-Ham Fighters
- 053 Pitcher (*)
- Uehara, Taiga
- ORIX Buffaloes
- 114 Pitcher (*)
- Uema, Towa
- Saitama Seibu Lions
- 0 Infielder
- Uemoto, Takashi
- Hiroshima Toyo Carp
- 38 Outfielder
- Ugusa, Koki
- Hiroshima Toyo Carp
- 66 Outfielder
- Ukai, Kosuke
- Chunichi Dragons
- 98 Catcher
- Umebayashi, Yuki
- Hokkaido Nippon-Ham Fighters
- 139 Outfielder (*)
- Umebinyuo, Okemu Mei
- Saitama Seibu Lions
- 2 Catcher
- Umeno, Ryutaro
- Hanshin Tigers
- 46 Pitcher
- Umeno, Yugo
- Chunichi Dragons
- 18 Pitcher
- Umetsu, Kodai
- Chunichi Dragons
- 62 Catcher
- Umino, Takashi
- Fukuoka SoftBank Hawks
- 46 Infielder
- Uno, Shinjiro
- Fukuoka SoftBank Hawks
- 32 Infielder
- Urata, Shunsuke
- Yomiuri Giants
- 34 Pitcher
- Urushihara, Taisei
- Hanshin Tigers
- 39 Catcher
- Usami, Shingo
- Chunichi Dragons
- 007 Infielder (*)
- Utsunomiya, Kisara
- Yomiuri Giants
- 10 Pitcher
- Uwasawa, Naoyuki
- Fukuoka SoftBank Hawks