The 1986 Japan Series was the 37th edition of Nippon Professional Baseball's postseason championship series. It matched the Central League champion Hiroshima Toyo Carp against the Pacific League champion Seibu Lions. The series is notable for being the only time to date in Japan Series history that an eighth game was played. After the first game ended in a tie, the Carp won the next three games. However, the Lions would respond by winning the next four in a row, reverse sweeping the Carp to capture their sixth Japan Series championship and their third title in five years.

NOTE: Game 1 was played to the 4:30:00 time limit. The time limit was reached in the 14h inning.

• 1986 World Series