Irene Jerotich Kosgei (born 8 September 1974) is a Kenyan long-distance runner who specialises in the marathon. Her first victory over the distance came at the Nairobi Marathon in 2006 and she won the race again in 2010 with a course record and personal best time of 2:28:47. She became the first Kenyan woman to win the Commonwealth marathon title at the 2010 Commonwealth Games in New Delhi.