Maria Teresa de Mascarenhas Horta Barros[1] (20 May 1937 – 4 February 2025) was a Portuguese feminist poet, journalist and activist.

The authors, known as the "Three Marias," were arrested, jailed and prosecuted under Portuguese censorship laws in 1972, during the last years of the Estado Novo dictatorship.

[3] The book and their trial inspired protests in Portugal and attracted international attention from European and American women's liberation groups in the years leading up to the Carnation Revolution.

[7] In 2021 she was awarded the Casino da Póvoa Literary Prize 2021, at the Correntes d'Escritas literature festival, for her work Estranhezas.

[11] Horta was the daughter of Jorge Augusto da Silva Horta, Bastonary of the Ordem dos Médicos (General Medical Council of Portugal) and a university professor, and his wife D. Carlota Maria Mascarenhas, of the Marquesses of Fronteira, Counts of Torre and Counts of Coculim, and also Marquesses of Alorna (formerly Marquesses of Castelo Novo) and Counts of Assumar.