Joaquim Renart i Garcia was a Spanish illustrator, painter, and decorator. He was the son of painter Dionís Renart i Bosch, in whose workshop he began his professional career, and brother of sculptor Dionisio Renart.

He studied at the Escuela de la Lonja and in the workshops of set designer Francesc Soler i Rovirosa, painter Francesc Torrescassana i Sallarés, and Ramón Martí Alsina. He also learned from Apel·les Mestres, who became a close friend.

He specialized in decorative work in gilding, polychroming, restoration of altarpieces, and copying works of art and antiques. He also excelled in the art of bookplate design, and in 1907 the Oliva de Vilanova publishing house published the book Els ex-libris de Renart, a magnificent example of the graphic arts of Modernism.

He was one of the founders of the Fomento de las Artes Decorativas (Promotion of Decorative Arts), president of the Círculo Artístico de San Lucas (San Lucas Artistic Circle) and the Orfeón Catalán (Catalan Choral Society), and a member of the Royal Academy of Fine Arts of San Jorge.

His monumental diary, 87 folders written between 1918 and 1961, one of the most extensive in the world, full of first-hand cultural and political references, is preserved in manuscript form in the Library of Catalonia, where some sixty albums of illustrations made by him are also kept, which complement it. The work is currently being published by Curial y Proa, and six volumes have been published so far (1995–2003).