Guillermo Haro Barraza (Spanish pronunciation: [gi'?e?mo 'a?o ßa'rasa]; 21 March 1913 – 26 April 1988) was a Mexican astronomer.
Through his own astronomical research and the formation of new institutions, Haro was influential in the development of modern observational astronomy in Mexico.
Internationally, he is best known for his contribution to the discovery of Herbig–Haro objects.