Rosa María Díez González (Sodupe, Güeñes, Vizcaya, 27 de mayo de 1952), más conocida como Rosa Díez, es una política española, diputada en el Congreso de los Diputados desde 2008.
Es cofundadora del partido Unión Progreso y Democracia, del que es también portavoz.
Hasta 2007 fue militante del Partido Socialista Obrero Español, partido con el que llegó a ser diputada foral de Vizcaya, parlamentaria del Parlamento Vasco, consejera del Gobierno Vasco (1991-1997) y europarlamentaria (1999-2007).
Rosa Díez González (born May 27, 1952 in Güeñes, Biscay, Spain) is a Spanish politician. She is a former Member of the European Parliament for the PSOE ("Partido Socialista Obrero Español" or Spanish Socialist Workers' Party), integrated in the Party of European Socialists.
In 2007 she gave up her seat and left the PSOE due to strong disagreement on what she perceived to be the Socialists' drift on individual liberties, ETA, and more. Subsequently she founded a new political party, UPyD ("Unión, Progreso y Democracia" or Union, Progress and Democracy), based on an already existing movement of basque citizens against terrorism of ETA. In 2008 and 2011, she was elected to the Congress of Deputies (Spain) representing Madrid district. In the last Spanish General Elections of 2011, she was re-elected, and her party was the fourth most voted party in Spain.