List of Mainstream Top 40 number-one hits of 2003 (U.S.)

This list of number-one hits on the Mainstream Top 40 charts in 2003. They were published by the U.S. magazine Billboard. This year there were 16 leaders.

• Eminem - Lose Yourself 7 weeks (November 23, 2002 - January 10, 2003 )

• 4 weeks ( 11 January to 7 February )

• 4 weeks ( 8 February to 7 March )

• 4 weeks ( March 8 to April 4 )

• 4 weeks ( April 5-May 2 )

• 4 weeks ( May 17-June 13 )

• 2 weeks ( June 14 to June 27 )

• 6 weeks ( June 28-August 8 )

• 6 weeks ( August 23 to October 3, a total of 7 weeks)

• 3 weeks ( October 4 to October 24 )

• 2 weeks ( 25 October to 7 November, a total of 6 weeks)

• 4 weeks ( November 15 to December 12, a total of 6 weeks)

• 9 weeks (December 13, 2003 - February 13, 2004 )