Bellator 138: Unfinished Business took place on June 19, 2015 at the Scottrade Center in St. Louis, Missouri. The event was headlined by a heavyweight bout between combat sports veterans Kimbo Slice and Ken Shamrock. Bellator 138 (Kimbo vs Shamrock) was the highest rated Bellator event ever. It did an average of 1.6 million viewers for the whole event and a peak of 2.4 million during the Kimbo vs Shamrock fight. And a DVR peak of 2.9 million. The previous high was Bellator 131 (Tito vs Bonnar) Which did 1.2 million average for the entire event and a peak of 2 million during the Tito vs Bonnar fight. And a DVR peak of 2.2 million
| Actor | Role |
|---|---|
 Ken KilpatrickNot listed | Not listed |
 Kimbo SliceNot listed | Not listed |
 Franklin Roberto LashleyNot listed | Not listed |
| DDan CharlesNot listed | Not listed |
 Patricio FreireNot listed | Not listed |
 Daniel WeichelNot listed | Not listed |
| DDaniel StrausNot listed | Not listed |
 Henry CorralesNot listed | Not listed |
| DDerek CamposNot listed | Not listed |
 Michael ChandlerNot listed | Not listed |