Ronald Kipkoech Korir (born 10 April 1991) is a Kenyan long-distance runner who competes in the marathon. A top-tier elite marathoner, his career is highlighted by a sub-2:05 personal best at the Berlin Marathon.
Korir began competing internationally around 2013, showing early promise with a sixth-place finish at the 2014 Frankfurt Marathon in 2:07:29. He remained a consistent performer in various international marathons for several years.
After an eighth-place finish at the 2022 Valencia Marathon in 2:05:37, Korir delivered a major breakthrough at the 2023 Berlin Marathon. Competing against a world-class field, he shattered his personal best by over a minute, finishing fourth with a time of 2:04:22. This result established him as one of the world's fastest marathon runners. He followed this with another fourth-place finish at the 2024 Hamburg Marathon.
In May 2025, the Athletics Integrity Unit (AIU) announced that Korir had been provisionally suspended for the presence or use of Triamcinolone Acetonide, a prohibited substance.