The following elections were held in the year 1803.
North America
- 1803 Connecticut's at-large congressional district special election
- 1803 Georgia's at-large congressional district special election
- 1803 United States House of Representatives elections in Kentucky
- 1803 United States House of Representatives elections in Maryland
- 1802–1803 United States House of Representatives elections in Massachusetts
- 1803 United States House of Representatives election in New Jersey
- 1803 New York's 6th congressional district special election
- 1803 New York's 7th congressional district special election
- 1803 United States House of Representatives elections in North Carolina
- 1803 United States House of Representatives election in Ohio
- 1803 United States House of Representatives elections in South Carolina
- 1803 United States House of Representatives election in Tennessee
- 1802–1803 United States House of Representatives elections in Vermont
- 1803 United States House of Representatives elections in Virginia
- 1802 and 1803 United States Senate elections