Authors born in 1803
- Adin Ballou Pacifist, 1803
- Albert Sidney Johnston Military , 1803
- Alexander Jackson Davis Architect, 1803
- Alexander Turney Stewart Businessman, 1803
- Alphonse Toussenel Naturalist, 1803
- Black Kettle Leader, 1803
- Catherine Crowe Writer, 1803
- Douglas Jerrold Dramatist, 1803
- Douglas William Jerrold Dramatist, 1803
- Edgar Quinet Linguist, 1803
- Edward Bulwer-Lytton, 1st Baron Lytton Writer, 1803
- Edward G. Bulwer-Lytton Politician, 1803
- George Borrow Writer, 1803
- George C. Kimble Commander, 1803
- George Henry Borrow Writer, 1803
- Hector Berlioz Composer, 1803
- John Ericsson Inventor, 1803
- John Sutter Businessman, 1803
- Paul Cullen Clergyman, 1803
- Ralph Waldo Emerson Philosopher, 1803
- Susanna Moodie Author, 1803
- William Edward Hickson Writer, 1803
- William Thoms Writer, 1803