1984 Japan Series

{{Short description|35th edition of Nippon Professional Baseball's postseason championship series}}

{{refimprove|date=October 2017}}

{{Infobox Japan Series

| image =

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| country = Japan

| year = 1984

| champion = Hiroshima Toyo Carp (4)

| champion_manager = Takeshi Koba

| champion_games = 75-45-10

| runnerup = Hankyu Braves (3)

| runnerup_manager = Toshiharu Ueda

| runnerup_games = 75-45-10

| date = October 13–22

| MVP = Kiyoyuki Nagashima (Hiroshima)

| FSA = Yukihiko Yamaoki (Hankyu)

| television =

| announcers =

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| umpires =

}}

The 1984 Japan Series was the 35th edition of Nippon Professional Baseball's postseason championship series. It matched the Central League champion Hiroshima Toyo Carp against the Pacific League champion Hankyu Braves. This was the fourth Japan Series appearance for the Carp, and the tenth appearance for the Braves. The Carp defeated the Braves in seven games to claim their third Japan Series championship.

As of 2024, this remains the last time that the Toyo Carp won the Japan Series, as the Carp are now the only remaining team in Nippon Professional Baseball to have won their most recent championship in the 20th century.