Jim Peyton is the main protagonist of Lost Planet 3, and is a new arrival on E.D.N. III. He crash lands on E.D.N. III with Dr. Kendrick Kovac later to be saved by his rival contractor Renard LaRoche. At some point, as the story of the game progresses, Jim gets captured by snow pirates led by Souichi who plans to execute him. Mira begs her father not to. As the story progresses Jim slowly discovers some dark secrets and learns the truth about NEVEC.
Jim and his grand-daughter Diana Peyton are stuck under rocks and wreckage, Diana tries to help her grandfather but it is in vain, as the rubble is too heavy to be lifted off of Jim's prosthetic leg. Jim tells her that he deserves this and tells her of his life on E.D.N III, and how it all led into him destroying Nushi and almost annihilating the humanity on E.D.N III. Jim apologizes to Diana, being sorry that she was born into such a life of hardships and conflict, rather than peace, soon asking her to forgive him for his mistake. After his death, his old friend Renard LaRoche blasts through some rocks, and after confirming Jim's death, comments that "if anyone's earned peace at last, it's him", followed by a good bye, as well as commenting that Jim didn't need to worry, for he had taught his grand-daughter well.
- Bill Watterson also did Jim's motion capture.
- After killing Isenberg, he gets a prosthetic leg.
- Jim starts Lost Planet 3 at age 32-Mid 60's.
- Despite working as a miner, he is hinted to have a decent level of military training.