Jacob Kiplimo was born in Kween, a village on the slopes of Mount Elgon in eastern Uganda, where he grew up watching his older brothers train and running about five kilometers to school each day. By 15, he had qualified for the 2016 Rio Olympics in the 5,000 meters, becoming Uganda's youngest-ever Olympian. His progression from there was relentless. At 16, he won gold in the U20 race at the 2017 World Cross Country Championships on home soil in Kampala. He took an Olympic bronze at Tokyo 2021 in the 10,000m, set a half marathon world record of 57:31 in Lisbon, and won the 2020 World Half Marathon title. His coach, Italian Iacopo Brasi, builds his training around threshold work and hill sessions at altitude in Kapchorwa. In 2025, Kiplimo moved up to the marathon. He placed second on debut at the London Marathon in 2:03:37, then returned five months later to win the Chicago Marathon in 2:02:23. At 24, his range across cross country, track, roads, and the marathon is unmatched among active distance runners.