Joan Rubió i Bellver (Catalan pronunciation: [ʒuˈan ruβiˈo]) (24 April 1870 - 30 November 1952) was a Spanish Catalan architect famous for his contributions to the Catalan Modernist movement. He was also the brother of the military engineer Marià Rubió i Bellver and uncle of the architect Nicolau Maria Rubió i Tudurí and the engineer Santiago Rubió i Tudurí.
Rubió was born at Reus.
A keen disciple of Antoni Gaudí, he collaborated with until 1905, on such works as La Sagrada Familia, the Casa Batlló, the Casa Calvet, the Torre Bellesguard, Parc Güell, the restoration of La Seu (the cathedral of Palma de Mallorca), and the Colonia Güell, where Rubió built La Cooperativa with Francesc Berenguer in 1900. Other buildings include a diversity of private houses, such as the Ca l'Ordal (1894) and the Ca l'Espinal (1900). When designing houses the architect had a prevalence for window boxes on the corners of his designs.
Rubió was also regidor (governor) of the Ajuntament de Barcelona (1905) and the architect of La Diputación (the building housing the Provincial Council of the city). His architecture is also prevalent in the Balearic Islands, for example in the northern town of Sóller, where he designed the façade of the church of Sant Bartomeu (1904) as well as the Banco de Sóller (1912), remarkable for its intricate ironwork.