| Climber Name | # Ascents Recorded | Notes |
|---|---|---|
| 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 | |
| Jakob Toft Pedersen | 1 | |
| Jakub Fábric | 1 | |
| James Dazhong Cook | 1 | |
| James H. Bell | 1 | |
| James Merriman Archer Thomson | 1 | |
| James Oswald | 1 | |
| James Thornton | 1 | |
| Jamie Cassidy | 1 | |
| Jamie Emerson | 1 |
References |
| Jan Długosz | 1 |