| Climber Name | # Ascents Recorded | Notes |
|---|---|---|
| Isaac Caldiero | 1 | |
| Isabelle Holloway | 1 | |
| Isabelle Patissier | 1 |
Isabelle was the first woman to climb 8b with her ascent of Sortillèges. |
| Isak Westin | 1 | |
| Issac Baxter | 1 | |
| Iziar Martinez | 1 | |
| Jacek Matuszek | 1 | |
| Jack Bradbrook | 1 | |
| Jack Mckechnie | 1 | |
| Jack Shipley | 1 | |
| Jacob Karrer | 1 | |
| Jacques Balmat | 1 |
1762-1834. Balmat was born in Savoy in the Chamonix valley, at the time part of the Kingdom of Sardinia. |
| Jacques de Lépiney | 1 | |
| Jacques Wehrlin | 1 | |
| Jake Bresnehan | 1 | |
| Jake Croft | 1 | |
| Jake Mason | 1 | |
| Jake Plasco | 1 | |
| Jakob Aberle | 1 | |
| Jakob Heber Norum | 1 |