| Initiate Dodge | 99 | Human |
| Initiate Ellison | 66 | Human |
| Initiate Fowler | 1 | Human |
| Initiate Gaines | 66 | Human |
| Initiate Hewsen | 66 | Human |
| Initiate Norland | 66 | Human |
| Initiate Norland | 66 | Human |
| Initiate Pappas | 66 | Human |
| Initiate Pappas | 66 | Human |
| Initiate Ramirez | 66 | Human |
| Initiate Tieggs | 1 | Human |
| Injured Scavenger | 66 | Human |
| Injured Super Mutant | 0.1 | Super Mutant |
| InspectUpIdle | 6 | Human |
| Insult Bot | 5 | Protectron |
| Intercom | 1 | Human |
| Intercom | 66 | Human |
| Interpreter Clarence | 1 | Human |
| Interrogatron | 17 | Assaultron |
| Irene The Irradiated | 100 | Human |
| Irradiated Cave Cricket | 30 | Cave Cricket |
| Irradiated Deathclaw | 21 | Deathclaw |
| Irradiated Feral Ghoul | 22 | Feral Ghoul |
| Irradiated Raider | 100 | Ghoul |
| Irradiated Snallygaster | 14 | Snallygaster |
| Irradiated Snallygaster | 14 | Snallygaster |
| Irradiated Wendigo Colossus | 100 | Wendigo Colossus |
| Irradiated Yao Guai | 41 | Yao Guai |
| Irritated Mole Miner | 95 | Mole Miner |
| Irritated Mole Miner | 95 | Mole Miner |
| Irritated Mole Rat Landminer | 95 | Mole Rat |
| Isela | 6 | Human |
| Jack Hunter | 66 | Human |
| Jack O' Lantern | 20 | Mr. Handy |
| Jack Woodhouse | 1 | Human |
| Jack-o'-lantern Heavy Laser Turret | 25 | Workshop Turret |
| Jack-o'-lantern Heavy Machinegun Turret | 15 | Tripod Turret |
| Jack-o'-lantern Laser Turret | 6 | Workshop Turret |
| Jack-o'-lantern Machinegun Turret | 4 | Tripod Turret |
| Jack-o'-lantern Missile Turret | 28 | Workshop Turret |
| Jack-o'-lantern Shotgun Turret | 20 | Workshop Turret |
| Jacky | 66 | Human |
| Jacob Lerner | 6 | Human |
| Jacque | 5 | Protectron |
| Jacqueline Murphy | 6 | Human |
| James | 1 | Human |
| James Oberlin | 1 | Ghoul |
| James Oberlin | 1 | Lost |
| Jasmine Greyson | 6 | Human |
| Jaxon Reed | 6 | Human |