Includes authors with at least 6 novels, short fiction, poems or collections:
| Debut Year | Author | Number of Titles |
|---|---|---|
| 1903 | Samuel Hopkins Adams | 7 |
| 1903 | A. C. Benson | 29 |
| 1903 | R. H. Benson | 38 |
| 1903 | Paul Busson | 7 |
| 1903 | Ellis Parker Butler | 18 |
| 1903 | Birdsall Otis Edey | 7 |
| 1903 | George Allan England | 40 |
| 1903 | Edgar Franklin | 40 |
| 1903 | L. P. Gratacap | 6 |
| 1903 | Richard Le Gallienne | 13 |
| 1903 | Maurice Level | 60 |
| 1903 | Minnie Martin | 10 |
| 1903 | A. A. Milne | 89 |
| 1903 | Cosimo Noto | 7 |
| 1903 | Owen Oliver | 14 |
| 1903 | Yei Theodora Ozaki | 23 |
| 1903 | Georgia Wood Pangborn | 39 |
| 1903 | Sax Rohmer | 125 |
| 1903 | Anna Wahlenberg | 9 |