Acha (also Achá) can be both a given name and surname. Notable people with the name include:
Acha Septriasa (born 1989), Indonesian actress and singer
Alberto Figueroa de Acha (born 1920), Bolivian football defender
Alexander Acha (born 1985), Mexican singer-songwriter
José Aguirre de Achá (born 1877), Bolivian writer, politician and lawyer
José María Achá (1810–1868), Bolivian military general and president of Bolivia
Mariano Acha (1799-1841), soldier who fought in the Argentine Civil War
Omar Acha (born 1971), Argentine historian and political essayist