Nancy Jebet Langat (born 22 August 1981) is a Kenyan middle distance runner who specialises in the 1,500 metres.

In 2010 Langat won the Diamond League 1500 m. She was undefeated in all races against the best runners in the world.

He performance at the 2010 IAAF Continental Cup was controversial, as she attempted to pull back Hind Dehiba as the two duelled in the final straight.

[1] She claimed an 800/1500 m middle distance double at the 2010 Commonwealth Games, however, and was chosen as the Kenyan Sportswoman of the Year in December.

[2] Langat had less success on the 2011 Diamond League circuit: on her two appearances, at the Golden Gala and Prefontaine Classic, she came fifth both times.