Pieter Casteels (1684–1749) was a Flemish painter who established his career in England, where he became known for his richly decorative still lifes of flowers, fruit and birds.

Born in Antwerp into a family of artists, Casteels moved to England in 1708 and quickly developed a successful reputation among patrons seeking fashionable interior decoration.

His compositions were often designed for specific architectural settings, including spaces above doors and fireplaces, resulting in distinctive formats and viewpoints.

Following the death of fellow flower and bird painter Jacob Bogdani in 1724, Casteels emerged as one of the leading artists of this decorative tradition in England. He continued to work there until his death in Richmond in 1749.