List of Oricon number-one singles of 2003
# List of Oricon number-one singles of 2003

The following is a list of Oricon number-one singles of 2003.

## Oricon Weekly Singles Chart

| Issue date | Song | Artist(s) |
| - | - | - |
| January 6 | "Love Me All Over" | J-FRIENDS |
| January 13 | "UNTITLED 4 BALLADS" | Every Little Thing |
| January 20 | "Chijou no Hoshi" | Miyuki Nakajima |
| January 27 | "Happy Life" | 175R |
| February 3 | "Kuki (STEM)" | Ringo Shiina |
| February 10 | "COLORS" | Hikaru Utada |
| February 17 | "COLORS" | Hikaru Utada |
| February 24 | "Tsuki no Shizuku" | RUI |
| March 3 | "Asu eno tobira" | I Wish |
| March 10 | "Asu eno tobira" | I Wish |
| March 17 | "Sekai ni Hitotsu Dake no Hana" | SMAP |
| March 24 | "Sekai ni Hitotsu Dake no Hana" | SMAP |
| March 31 | "Sekai ni Hitotsu Dake no Hana" | SMAP |
| April 7 | "It's Showtime!" | B'z |
| April 14 | "Sekai ni Hitotsu Dake no Hana" | SMAP |
| April 21 | "Eien no BLOODS" | KinKi Kids |
| April 28 | "Sora ni utaeba" | 175R |
| May 5 | "As for One Day" | Morning Musume |
| May 12 | "Sakura" | Naotarō Moriyama |
| May 19 | "Sakura" | Naotarō Moriyama |
| May 26 | "Sakura" | Naotarō Moriyama |
| June 2 | "Super Lover" | w-inds |
| June 9 | "Darling" | V6 |
| June 16 | "Hello" | Hyde |
| June 23 | "KI" | Kōshi Inaba |
| June 30 | "Kokoro ni yume o kimi ni wa ai" | KinKi Kids |
| July 7 | "Katte ni Sindbad" | Southern All Stars |
| July 14 | "Cosmic Rescue" | V6 |
| July 21 | "&" | Ayumi Hamasuki |
| July 28 | "Yasei no ENERGY" | B'z |
| August 4 | "Namida no umi de dakaretai" | Southern All Stars |
| August 11 | "Namida no umi de dakaretai" | Southern All Stars |
| August 18 | "Ashita e Kaeru" | Chemistry |
| August 25 | "Hakka Candy" | KinKi Kids |
| September 1 | "Forgiveness" | Ayumi Hamasuki |
| September 8 | "Niji / Himawari / Sore ga Subete sa" | Masaharu Fukuyama |
| September 15 | "Niji / Himawari / Sore ga Subete sa" | Masaharu Fukuyama |
| September 22 | "Niji / Himawari / Sore ga Subete sa" | Masaharu Fukuyama |
| September 29 | "Niji / Himawari / Sore ga Subete sa" | Masaharu Fukuyama |
| October 6 | "Niji / Himawari / Sore ga Subete sa" | Masaharu Fukuyama |
| October 13 | "Ambitious Japan!" | Tokio |
| October 20 | "Imitation Gold" | Tak Matsumoto feat. Mai Kuraki |
| October 27 | "Beautiful Dreamer/Street Life" | Glay |
| November 3 | "Hokōsha yūsen" | Yuzu |
| November 10 | "Long Road" | w-inds |
| November 17 | "No way to say" | Ayumi Hamasaki |
| November 24 | "Yumemonogatari" | Tackey & Tsubasa |
| December 1 | "Tenohira" | Mr. Children |
| December 8 | "Tenohira" | Mr. Children |
| December 15 | "Lack" | Porno Graffiti |
| December 22 | "Yorokobi no Uta" | MONGOL800 |
| December 29 | "Yorokobi no Uta" | MONGOL800 |
