The highest-selling singles in Japan are ranked in the Oricon Singles Chart, which is published by Oricon Style magazine.[1] 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 1968.
| Issue date | Song | Artist(s) | Ref. |
|---|---|---|---|
| January 4 | "Love You Tokyo" | Los Primos | [2] |
| January 11 | |||
| January 18 | |||
| January 25 | "Kaette Kita Yopparai" | The Folk Crusaders | |
| February 1 | |||
| February 8 | |||
| February 15 | |||
| February 22 | |||
| February 26 | "Koi no Shizuku" | Yukari Itō | |
| March 4 | |||
| March 11 | |||
| March 18 | |||
| March 25 | "Yūbe no Himitsu" | Tomoko Ogawa | |
| April 1 | "Massachusetts" Japanese title: (マサチューセッツ) |
Bee Gees | |
| April 8 | "Koi no Shizuku" | Yukari Itō | |
| April 15 | "Hana no Kubikazari / Ginga no Romance" | The Tigers | |
| April 22 | |||
| April 29 | |||
| May 6 | |||
| May 13 | |||
| May 20 | |||
| May 27 | |||
| June 3 | "Hoshikage no Waltz" | Masao Sen | |
| June 10 | |||
| June 17 | |||
| June 24 | |||
| July 1 | |||
| July 8 | "Emerald no Densetsu" | The Tempters | |
| July 15 | |||
| July 22 | "C C C" | The Tigers | |
| July 29 | |||
| August 5 | |||
| August 12 | |||
| August 19 | "Hoshikage no Waltz" | Masao Sen | |
| August 26 | "C C C" | The Tigers | |
| September 2 | |||
| September 9 | "The Sound of Silence" Japanese title: (サウンド・オブ・サイレンス) |
Simon & Garfunkel | |
| September 16 | |||
| September 23 | "Koi no Kisetsu" | Pinky & Killers | |
| September 30 | |||
| October 7 | |||
| October 14 | |||
| October 21 | |||
| October 28 | |||
| November 4 | |||
| November 11 | |||
| November 18 | |||
| November 25 | |||
| December 2 | |||
| December 9 | |||
| December 16 | "Ima wa Shiawasekai" | Mitsuo Sagawa | |
| December 23 | "Koi no Kisetsu" | Pinky & Killers | |
| December 30 |