María Teresa Ruiz (born 24 September 1946) is a Chilean astronomer who was the first woman to receive Chile's National Prize for Exact Sciences.
She is also known by the discovery of the brown dwarf named as Kelu-1.In 2018 she was part of the top 10 of the most powerful and influential women in Chile due to her studies and scientific contributions.During her career she has written two books about astronomy; the first one Desde Chile un cielo estrellado: lecturas para fascinarse con la astronomía (2013) and the second one Hijos de las Estrellas (2017)