Esquerra Republicana de Catalunya (Republican Left of Catalonia), or ERC, is a left-of-centre political party that campaigns for independence for Catalonia from Spain.

Led by Francesc Maciŕ in 1931, the party declared an independent Catalan Republic that was curtailed by the new Constitution of the Second Spanish Republic.

Led by Lluís Companys, in 1935 the party declared an independent Catalan Republic, however the party leaders (including Companys) were arrested and jailed for this.

In 1936 the party decided to become part of the Spanish Popular Front to contest that years election which it won. Esquerra became the leading force of the Popular Front in Catalonia and tried to maintain the unity of the Front in face of growing tensions between the POUM and Communists.

The party was declared illegal (along with all other participants in the Popular Front) by Francisco Franco after he came to power in 1939.

Esquerra Republicana de Catalunya has (2003) 23 seats in the Catalan Parliament in Barcelona. Its current leader is Josep-Lluís Carod-Rovira.