The year 2015 was the first year in the history of the Rizin Fighting Federation, a mixed martial arts promotion based in Japan. Only two events were held this year, both consisting of the Rizin World Grand-Prix 2015. Rizin events are broadcast through a television agreement with Fuji Television.
On September 19, 2015 during Bellator 142 Dynamite 1 event, it was announced that Pride FC co-founder Nobuyuki Sakakibara had signed former Pride Heavyweight Champion The Last Emperor Fedor Emelianenko to headline his new promotion’s New Year’s Eve Show in Tokyo.
On October 8, 2015 The former President of Pride FC, Sakakibara held a press conference to announce his return to MMA with Rizin Fighting Federation.
Sakakibara returned to mainstream MMA, along with Nobuhiko Takada and other former Pride FC employees.
Rizin partnered with Bellator MMA to allow former Strikeforce Light Heavyweight Champion, Muhammed "King Mo" Lawal to compete the Rizin's inaugural grand prix. Eventually, King Mo won the 8 man Heavyweight tournament with a prize of $300,000.
| Event | Date | Venue | Location | Attendance | ||
|---|---|---|---|---|---|---|
| 1 | Saitama Super Arena |  Saitama, Japan | 12,214 | |||
| 2 | Saitama, Japan | 18,365 |
| Rizin World Grand Prix 2015: Part 1 - Saraba | |
| Promotion: | Rizin Fighting Federation |
| Date: | December 29, 2015 |
| City: | Saitama, Japan |
Rizin World Grand Prix 2015: Part 1 - Saraba was an inaugural mixed martial arts event held by the Rizin Fighting Federation on December 29, 2015 at the Saitama Super Arena in Saitama, Japan.
| Rizin World Grand Prix 2015: Part 2 - Iza | |
| Promotion: | Rizin Fighting Federation |
| Date: | December 31, 2015 |
| City: | Saitama, Japan |
Rizin World Grand Prix 2015: Part 2 - Iza was a mixed martial arts event held by the Rizin Fighting Federation on December 31, 2015 at the Saitama Super Arena in Saitama, Japan.