Melquíades Álvarez Gónzalez-Posada (Gijón, May 17, 1864 - Madrid, August 22, 1936) was a Spanish Republican politician, founder and leader of the Reformist Republican Party (Partido Republicano Reformista), commonly known just as Reformist Party.
He studied Law at the University of Oviedo and collaborated with Asturian liberal newspapers. In 1898 he was elected to the Congress as Liberal candidate and was appointed Professor of Roman Law at the University of Oviedo. In 1899, he turned into Republican and in 1906 he was elected Republican congressman. He was one of the organizers of the Liberal Block in 1908 against the Conservative Prime Minister Antonio Maura and of the Republican-Socialist Conjunction in 1909. In 1912, he founded with Gumersindo de Azcárate and José Ortega y Gasset the Reformist Party and the League for the Spanish Political Education. In the 1914 elections, 11 Reformist congressmen were elected. It had also a great success in the municipal elections in Asturias. During the Second Republic he founded the Democratic Liberal Republican Party (Partido Republicano Liberal Democrático), but its electoral results were poor: two deputies in 1932 and ten in 1933, when they supported the right-wing government backed by the Spanish Confederation of the Autonomous Right (CEDA). After the beginning of the Civil War, the revolutionary militias imprisoned and killed him.