Spanish historic trade‑union leader.

He was the son of Nicolás Redondo Blanco, a member of Unión General de Trabajadores (UGT/General Union of Workers) and Partido Socialista Obrero Español (PSOE/Spanish Socialist Worker's Party), who had participated in the revolutionary coup d'état of 1934 and later in the civil war on the Republican side.

After the end of the war Nicolás Redondo was evacuated to France and welcomed by a family. He was repatriated at the beginning of the Second World War. His father was sentenced to death, but this sentence was commuted to prison and he was released years later.

He started working at the Sestao Naval as apprentice adjuster, remaining in this company for more than 30 years. He joined the UGT and the PSOE in 1945, participating in the organization of strikes and demonstrations and in the distribution of propaganda. The most important of these acts was the Bilbao strike of 1947, considered the first major strike of the Franco era.

In 1951 he was arrested and imprisoned for his trade union activity. Despite this, his activity did not cease. A proof of this were his constant trips to France, in which, in addition to conducting training courses, he had his first contacts with socialist leaders in exile.

During the 60s, in view of the economic and social modernization of the country, the labour movement underwent a momentous change. Strikes became increasingly common and far‑reaching; two clear examples were the strike of 1962 and the Huelga de Bandas (strike) of 1967. His intense activity of these years had as a consequence the frequent arrests of Nicolás Redondo by the forces of public order, until being exiled to Las Hurdes (Cáceres) in 1967.

His signiricance within the organization was increasing progressively. Nicolás Redondo was one of the members in charge of establishing the UGT Executive Committee in the interior. He participated in PSOE congresses in exile and he was immersed in the great ideological debates of Spanish socialism of the time. In 1976 he was elected UGT Secretary‑General. He was elected deputy for Vizcaya in four parliamentary terms (1977-1987). He left his position as UGT Secretary‑General in the 36th Congress of the union, held in 1994. He was replaced by Cándido Méndez and he also withdrew from all political and trade‑union activity.