The 2021 Japan Series was the championship series of Nippon Professional Baseball's 2021 season. The 72nd edition of the Japan Series, it was a best-of-seven playoff between the Orix Buffaloes and Tokyo Yakult Swallows, the winners of the Pacific and Central League's Climax Series, respectively. Both teams were the winners of their respective league's regular season championship.
A mid-season hiatus for the 2020 Summer Olympics and other game postponements required the Japan Series to be pushed back into late November, requiring some games to be played at stadiums other than the team's usual home fields due to scheduling conflicts. The series began on November 20 and concluded on November 27. The Swallows won the series, 4–2. It was their sixth Japan Series title in franchise history and their first since 2001. Yuhei Nakamura of Yakult won the Japan Series Most Valuable Player Award.