This lists songs that hit number one on the charts in the US during 2004. If a song spent nonconsecutive weeks at number one, the number of weeks for each occurrence at the top is shown in parenthesis.
| Date | Artist - Title | Weeks at #1 |
| December 7 2003 – February 7 2004 | OutKast - Hey Ya! | 9 |
| February 8 – 14 2004 | OutKast feat. Sleepy Brown - The Way You Move | 1 |
| February 15 – 21 2004 | Twista feat. Kanye West and Jamie Foxx - Slow Jamz | 1 |
| February 22 – May 15 2004 | Usher feat. Lil Jon and Ludacris - Yeah! | 12 |
| May 16 – July 3 2004 | Usher - Burn | 8 (7) |
| July 4 – 10 2004 | Fantasia - I Believe | 1 |
| July 11 – 17 2004 | Usher - Burn | 8 (1) |
| July 18 – 31 2004 | Usher - Confessions Part II | 2 |
| August 1 – 14 2004 | Juvenile feat. Soulja Slim - Slow Motion | 2 |
| August 15 – September 4 2004 | Terror Squad - Lean Back | 3 |
| September 5 – October 23 2004 | Ciara feat. Petey Pablo - Goodies | 7 |
| October 24 – December 4 2004 | Usher and Alicia Keys - My Boo | 6 |
| December 5 – 25 2004 | Snoop Dogg feat. Pharrell - Drop It Like It's Hot | 3 |
| December 26 2004 – February 26 2005 | Mario - Let Me Love You | 9 |
13 different songs hit number one in the US during 2004.
Top 5 Songs of 2004
1: Usher feat Lil Jon & Ludacris - Yeah!
2: Usher - Burn
3: Alicia Keys - If I Ain't Got You
4: Maroon5 - This Love
5: Outkast feat Sleepy Brown - The Way You Move
2: Usher - Burn
3: Alicia Keys - If I Ain't Got You
4: Maroon5 - This Love
5: Outkast feat Sleepy Brown - The Way You Move