The highest-selling singles in Japan are ranked in the Oricon Singles Chart, which is published by Oricon Style magazine. The data are compiled by Oricon based on each singles' physical sales. This list includes the singles that reached the number one place on that chart in 1989.
| Issue date | Song | Artist(s) | Ref. |
|---|---|---|---|
| January 2 | "" | Tsuyoshi Nagabuchi | [1] |
| January 9 | |||
| January 16 | "Aki" | Otokogumi | |
| January 23 | "Koi Hitoyo" | Shizuka Kudo | |
| January 30 | |||
| February 6 | "True Love" | Yui Asaka | |
| February 13 | "Ai ga Tomaranai (Turn It into Love)" | Wink | |
| February 20 | "" | Tsuyoshi Nagabuchi | |
| February 27 | |||
| March 6 | "Rosécolor" | Miho Nakayama | |
| March 13 | "Time Zone" | Otokogumi | |
| March 20 | "" | Hikaru Genji | |
| March 27 | "Namida wo Misenai de (Boys Don't Cry)" | Wink | |
| April 3 | |||
| April 10 | |||
| April 17 | "Be My Baby" | Complex | |
| April 24 | |||
| May 1 | "" | Toshihiko Tahara | |
| May 8 | "Liar" | Akina Nakamori | |
| May 15 | "Arashi no Sugao" | Shizuka Kudo | |
| May 22 | |||
| May 29 | |||
| June 5 | "Return to Myself (Shinai, Shinai, Natsu.)" | Mari Hamada | |
| June 12 | "Diamonds" | Princess Princess | |
| June 19 | "Sayonara Baby" | Southern All Stars | |
| June 26 | "Diamonds" | Princess Princess | |
| July 3 | "" | Shonentai | |
| July 10 | "Sekai de Ichiban Atsui Natsu" | Princess Princess | |
| July 17 | "Samishii Nettaigyo" | Wink | |
| July 24 | |||
| July 31 | "" | Hikaru Genji | |
| August 7 | "" | Kyosuke Himuro | |
| August 14 | "" | Otokogumi | |
| August 21 | "" | Hikaru Genji | |
| August 28 | |||
| September 4 | |||
| September 11 | |||
| September 18 | "Kōsa ni Fukarete" | Shizuka Kudo | |
| September 25 | |||
| October 2 | |||
| October 9 | |||
| October 16 | |||
| October 23 | |||
| October 30 | "" | Misato Watanabe | |
| November 6 | "" | Tetsuya Komuro | |
| November 13 | "One Night in Heaven (Mayonaka no Angel)" | Wink | |
| November 20 | |||
| November 27 | "Gravity of Love" | Tetsuya Komuro | |
| December 4 | "" | Jun Sky Walker(s) | |
| December 11 | "" | Yoko Minamino | |
| December 18 | "" | Tsuyoshi Nagabuchi | |
| December 25 | "Christmas Eve" | Tatsuro Yamashita |