The 30th Meijin was the 30th Meijin tournament of the board game go. The tournament was held in 2005 in Japan and was won by Cho U.
Challenger Group
| Players | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | T | 
| Yoda Norimoto | X | Loss | Loss | Loss | Won | Loss | Won | Won | Loss | 3 | 
| Kobayashi Satoru - C | Won | X | Won | Won | Won | Loss | Won | Won | Won | 7 | 
| Imamura Toshiya | Won | Loss | X | Loss | Won | Won | Won | Loss | Won | 5 | 
| Yamashita Keigo - C | Won | Loss | Won | X | Won | Won | Won | Won | Won | 7 | 
| O Meien | Loss | Loss | Loss | Loss | X | Won | Won | Won | Loss | 3 | 
| Yamada Kimio | Won | Won | Loss | Loss | Loss | X | Won | Won | Loss | 4 | 
| Cho Sonjin | Loss | Loss | Loss | Loss | Loss | Loss | X | Loss | Won | 1 | 
| Ogata Masaki | Loss | Loss | Won | Loss | Loss | Loss | Won | X | Loss | 2 | 
| Sakai Hideyuki | Won | Loss | Loss | Loss | Won | Won | Loss | Won | X | 4 | 
Challenger Final
Final
| Players | 1 | 2 | 3 | 4 | 5 | 6 | 7 | T | 
| Cho U (Meijin) | Won | Won | Won | Loss | Loss | Loss | Won | 4 | 
| Kobayashi Satoru | Loss | Loss | Loss | Won | Won | Won | Loss | 3 | 
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| Past editions | 
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| Past winners |  | 
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| Honorary winners |  | 
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