Plaça del Rei (meaning "King's Square" in Catalan, in Spanish: Plaza del Rey) is a 14th-century medieval public square in the Barri Gòtic of Barcelona, Catalonia, Spain.^[1]

The square is surrounded by the Palau Reial Major including the Saló del Tinell, the Palau del Lloctinent ("Lieutenant's Palace"), the 15th-century tower Mirador del Rei Martí ("King Martin's Watchtower"), and the Capella Reial de Santa Àgata ("Royal Chapel of St Agatha"). On its southern side stands Casa Padellàs (Padellàs's House) a 15th–16th century palazzo moved here stone by stone from Mercaders Street in 1931 and since 1943, has housed the Barcelona City History Museum (MUHBA).

Topos V, a work by Eduardo Chillida, underlines one of the corners of the square.