#1 Singles and Albums in 2003 according to Oricon
From January 1, 2003 to December 31, 2003. Click on the # for that week to view the top 10 albums, singles and their sales. The date to the left of the week is the monday of the week (i.e., the first day of the Oricon week). This may or may not match up to the date that the single/album was released, as most releass dates state the Wednesday as its release date (yet are on sale the Tuesday before).
- Note: 'Week Sales' means the number of units that the product sold to get to #1 for that week. Usually this is the product's first week sales, but not always.
| # | Date | Single Artist | Single | Week Sales | Album Artist | Album | Week Sales |
| 1 | 12.30 | Every Little Thing | UNTITLED ~4ballads~ | 110,315 | Hamasaki Ayumi | RAINBOW | 571,027 |
| 2 | 01.06 | Nakajima Miyuki | Chijyou no Hoshi / Head Light Tail Light | 40,604 | CHEMISTRY | Second to None | 1,075,872 |
| 3 | 01.13 | 175R | Happy Life | 63,168 | CHEMISTRY | Second to None | 402,109 |
| 4 | 01.20 | Shiina Ringo | Stem ~Daimyou Asobi Hen~ | 116,198 | Hirai Ken | LIFE is... | 351,258 |
| 5 | 01.27 | Utada Hikaru | COLORS | 437,903 | BoA | VALENTI | 615,218 |
| 6 | 02.03 | Utada Hikaru | COLORS | 139,829 | BoA | VALENTI | 222,851 |
| 7 | 02.10 | RUI | Tsuki no Shizuku | 114,040 | EXILE | Styles Of Beyond | 145,102 |
| 8 | 02.17 | I WiSH | Asu he no Tobira | 180,006 | Shiina Ringo | Kalk Samen Kuri no Hana | 165,316 |
| 9 | 02.24 | I WiSH | Asu he no Tobira | 111,676 | Shiina Ringo | Kalk Samen Kuri no Hana | 136,214 |
| 10 | 03.03 | SMAP | Sekai ni Hitotsu Dake no Hana | 630,399 | t.A.T.u. | t.A.t.U | 64,503 |
| 11 | 03.10 | SMAP | Sekai ni Hitotsu Dake no Hana | 380,002 | Hamasaki Ayumi | A BALLADS | 561,127 |
| 12 | 03.17 | SMAP | Sekai ni Hitotsu Dake no Hana | 300,150 | Yuzu | Sumire | 256,327 |
| 13 | 03.24 | B'z | IT'S SHOWTIME! | 308,262 | Morning Musume | No.5 | 122,136 |
| 14 | 03.31 | SMAP | Sekai ni Hitotsu Dake no Hana | 99,592 | Every Little Thing | Many Pieces | 53,715 |
| 15 | 04.07 | KinKi Kids | Eien no BLOODS | 245,045 | t.A.T.u. | t.A.t.U | 47,857 |
| 16 | 04.14 | 175R | Sora ni Utaeba | 130,768 | HY | Street Story | 106,278 |
| 17 | 04.21 | Morning Musume | AS FOR ONE DAY | 84,251 | HY | Street Story | 103,245 |
| 18 | 04.28 | Moriyama Naotaro | Sakura | 94,536 | HY | Street Story | 93,736 |
| 19 | 05.05 | Moriyama Naotaro | Sakura | 105,256 | HY | Street Story | 86,912 |
| 20 | 05.12 | Moriyama Naotaro | Sakura | 86,254 | Nagabuchi Tsuyoshi | Keep On Fighting | 90,524 |
| 21 | 05.19 | w-inds. | SUPER LOVER ~I need you tonight~ | 78,311 | t.A.T.u. | t.A.t.U | 61,529 |
| 22 | 05.26 | V6 | Darling | 111,068 | Various Artists | 8 Mile Soundtrack | 54,216 |
| 23 | 05.31 | HYDE | HELLO | 98,325 | Various Artists | 8 Mile Soundtrack | 48,761 |
| 24 | 06.07 | Inaba Koshi | KI | 200,157 | Metallica | St. Anger | 51,416 |
| 25 | 06.14 | KinKi Kids | Kokoro ni Yume wo Kimi ni wa Ai wo / Gira☆Gira | 214,178 | CHEMISTRY | Between the Lines | 361,265 |
| 26 | 06.21 | Southern All Stars | Katte ni Sindbad | 219,165 | SMAP | SMAP 016/MIJ | 305,268 |
| 27 | 06.28 | V6 | COSMIC RESCUE / Tsuyoku Nare | 78,422 | CHEMISTRY | Between the Lines | 66,123 |
| 28 | 07.05 | Hamasaki Ayumi | & | 287,002 | Kuraki Mai | If I Believe | 251,218 |
| 29 | 07.12 | B'z | Yasei no ENERGY | 230,019 | RIP SLYME | TIME TO GO | 225,671 |
| 30 | 07.19 | Southern All Stars | Namida no Umi de Dakaretai ~SEA OF LOVE~ | 365,108 | Dragon Ash | HARVEST | 252,812 |
| 31 | 07.26 | Southern All Stars | Namida no Umi de Dakaretai ~SEA OF LOVE~ | 122,714 | Yuzu | Yuzu Smile | 115,458 |
| 32 | 08.02 | CHEMISTRY | Ashita e Kaeru / Us | 102,461 | V6 | ∞INFINITY ~LOVE & LIFE~ | 75,412 |
| 33 | 08.09 | KinKi Kids | Hakka Candy | 260,885 | 12 Girls Band | 12 Girls Band ~Beautiful Energy~ | 118,568 |
| 34 | 08.16 | Hamasaki Ayumi | forgiveness | 132,092 | 12 Girls Band | 12 Girls Band ~Beautiful Energy~ | 201,241 |
| 35 | 08.23 | Fukuyama Masaharu | Niji / Himawari / Sore ga Subetesa | 356,629 | Fukuyama Masaharu | fukuyama masaharu MAGNUM COLLECTION "SLOW" | 211,457 |
| 36 | 08.30 | Fukuyama Masaharu | Niji / Himawari / Sore ga Subetesa | 152,592 | Hajime Chitose | Nomad Soul | 125,645 |
| 37 | 09.06 | Fukuyama Masaharu | Niji / Himawari / Sore ga Subetesa | 100,915 | Every Little Thing | Every Best Single 2 | 281,571 |
| 38 | 09.13 | Fukuyama Masaharu | Niji / Himawari / Sore ga Subetesa | 71,493 | B'z | BIG MACHINE | 500,237 |
| 39 | 09.20 | Fukuyama Masaharu | Niji / Himawari / Sore ga Subetesa | 67,486 | Road of Major | ROAD OF MAJOR | 176,265 |
| 40 | 09.27 | TOKIO | AMBITIOUS JAPAN! | 72,348 | Ketsumeishi | Ketsunopolis 3 | 290,751 |
| 41 | 10.04 | TAK MATSUMOTO feat.Kuraki Mai | Imitation Gold | 42,312 | Ketsumeishi | Ketsunopolis 3 | 97,821 |
| 42 | 10.11 | GLAY | BEAUTIFUL DREAMER / STREET LIFE | 121,536 | Aiuchi Rina | A.I.R | 95,243 |
| 43 | 10.18 | Yuzu | Hokousha Yuusen / Koi | 75,214 | KinKi Kids | G album -24/7- | 242,826 |
| 44 | 10.25 | w-inds. | Long Road | 66,743 | Takeuchi Mariya | Longtime Favorites | 143,218 |
| 45 | 11.01 | Hamasaki Ayumi | No way to say | 176,229 | Nakashima Mika | LOVE | 437,218 |
| 46 | 11.08 | Tackey & Tsubasa | Yume Monogatari | 72,609 | Nakashima Mika | LOVE | 213,517 |
| 47 | 11.15 | Mr.Children | Tenohira / Kurumi | 286,982 | KICK THE CAN CREW | BEST ALBUM 2001-2003 | 155,768 |
| 48 | 11.22 | Mr.Children | Tenohira / Kurumi | 73,755 | aiko | Akatsuki no Love Letter | 232,422 |
| 49 | 11.29 | Porno Graffitti | Lack | 59,014 | EXILE | EXILE ENTERTAINMENT | 395,257 |
| 50 | 12.06 | Mongol800 | Yorokobi no Uta | 51,733 | EXILE | EXILE ENTERTAINMENT | 195,741 |
| 51 | 12.13 | Mongol800 | Yorokobi no Uta | 32,362 | Hamasaki Ayumi | Memorial address | 524,028 |
| 52 | 12.20 | SMAP | Sekai ni Hitotsu Dake no Hana | 72,267 | Kuraki Mai | Wish You The Best | 450,127 |
| 53 | 12.28 | N/A | N/A | N/A | N/A | N/A | N/A |