António Duarte Arnaut, GOL (28 January 1936 – 21 May 2018) was a Portuguese poet, fiction writer, essayist, lawyer, and politician.

He was Minister of Social Affairs in the II Constitutional Government of Portugal, led by Mário Soares.

He is considered the "father" of the Portuguese national health service (SNS - Serviço Nacional de Saúde), having created the first basic health law in Portugal and contributed to universal access to medical care for all Portuguese.

António Arnaut was born in Cumeeira, a small town located in Penela Municipality.

In 1973, together with personalities like Mário Soares or Salgado Zenha, he founded the Socialist Party, in Bad Münstereifel, Germany.