The 2019 Pacific League Climax Series (PLCS) was a post-season Climax Series playoff consisting of two consecutive series that determined which of the three teams who finished in the top three during the 2019 regular season would represent the Pacific League in the Japan Series. The First Stage was a best-of-three series played between the second-place hosts Fukuoka SoftBank Hawks and the third-place Tohoku Rakuten Golden Eagles. The series was played between October 5 to 7. The Hawks defeated the Eagles 2–1 and advanced to the Final Stage to face the pennant-winning Saitama Seibu Lions.

The Climax Series is the current annual playoff system implemented by Japan's Nippon Professional Baseball (NPB). It determines which team from the Central League (CL) and from the Pacific League (PL) will advance to compete for the championship in the Japan Series. After the creation of the NPB's two-league system in 1950, the PL experimented with three different playoff systems. In 2004, it implemented the postseason structure from which the Climax Series is based. After three seasons, the CL adopted the same system in 2007, creating the current, unified playoff format.