Mirtha is a female given name. Notable people with the name include:
Mirtha Brock (born April 9, 1970), Colombian athlete Mirtha Colón (born 1951), Honduran activist Mirtha Dermisache (1940–2012), Argentine artist Mirtha Legrand (born 1927), Argentine actress and television presenter Mirtha Marrero, Cuban pitcher Mirtha Michelle (born 1984), American actress Mirtha N. Quintanales, Cuban feminist and writer Mirtha Reid (1918–1981), Uruguayan actress Mirtha Rivero (born 1956), Venezuelan journalist and writer Mirtha Vásquez (born 1975), Peruvian lawyer