Bellator 166: Dantas vs. Warren 2 was held on December 2, 2016 at the WinStar World Casino in Thackerville, Oklahoma. The event aired live in prime time on Spike TV. The event was headlined by a title fight rematch as Eduardo Dantas defended the Bellator Bantamweight Championship against former champion Joe Warren. Dantas had won back to back fights since losing the Bellator bantamweight title to Warren at Bellator 128 in 2014. Warren was coming off a submission win against Sirwan Kakai at Bellator 161. A fight between featherweight prospects A.J. McKee and Emmanuel Sanchez was scheduled for the co-main event. However, Sanchez pulled out in late November due to injury and was replaced by Ray Wood. Wood had been scheduled to face Treston Thomison on the preliminary card so Thomison received a new opponent in Dawond Pickney.