Hellen Onsando Obiri is a Kenyan distance runner who transitioned from a decorated track career to marathon dominance. She is the only woman to have won world titles in indoor track, outdoor track, and cross country, and won Olympic 5000m silver in 2016 and 2020.
Obiri made her marathon debut in New York in 2022 before winning back-to-back Boston Marathon titles in 2023 and 2024. She set her marathon personal best of 2:21:38 at Boston in 2023 and added a New York City Marathon victory in November 2023. She finished second to Sharon Lokedi at the 2025 Boston Marathon as Lokedi broke the course record.
She trains with the On Athletics Club in Boulder, Colorado under coach Dathan Ritzenhein.