The 66th Honinbo began league play on 7 October 2010 and completed on July 21, 2011.
Hane Naoki, Iyama Yuta, Takao Shinji, and Cho U retained their place in the Honinbo league from the 65th Honinbo.
These players were joined by the winners of the preliminary tournament: Cho Sonjin, Seto Taiki, O Rissei, and Kobayashi Satoru.
League play commenced on 7 October after the preliminaries, which finished on 2 September.
Hane Naoki, who lost the Honinbo title to Yamashita Keigo the year prior, won the right to challenge Keigo for the title.