The Natsu Onna Kettei Tournament (夏女決定トーナメント Natsu Onna Kettei Tōnamento?) was an annual professional wrestling tournament promoted by the JWP Joshi Puroresu promotion between 2009 and 2012. The name of the tournament was Japanese for "Summer Woman Determination Tournament" and as the name suggests, it was held during the summer. The tournament was contested in a single-elimination format, however, uniquely, every other tournament was for singles wrestlers and every other for tag teams of two wrestlers. Throughout the years, the tournament featured several outside participants, most notably from the Ice Ribbon promotion, with which JWP co-produced the 2012 "JRibbon" tournament. Kaori Yoneyama is the only wrestler to have won the tournament twice; once as a singles wrestler and once teaming with Command Bolshoi.
The first ever Natsu Onna Kettei Tournament took place during two shows on August 2, 2009. The tournament featured fourteen singles wrestlers, including six outside participants; Ayako Sato from Ito Dojo, freelancers Chihiro Oikawa, Megumi Yabushita and Toshie Uematsu, Makoto from Ice Ribbon and Yumi Ohka from Pro Wrestling Wave. Oikawa and Makoto were granted automatic spots in the second round of the tournament. The eventual tournament winner, Kaori Yoneyama, went on to unsuccessfully challenge Kayoko Haruyama for the JWP Openweight Championship on October 4.