Maria de Lourdes Ruivo da Silva de Matos Pintasilgo, (); (Abrantes, São João Baptista, 18 January 1930 – Lisbon, 10 July 2004) was a Portuguese chemical engineer and politician. She was the first and to date only woman to serve as Prime Minister of Portugal, and the second woman to serve as Prime Minister in Western Europe, after Margaret Thatcher.