Osvald Sirén (6 April 1879 – 26 June 1966) was a Finnish-born Swedish art historian, whose interests included the art of 18th century Sweden, Renaissance Italy and China.
Sirén was born in Helsinki. He held the J.A. Berg Professorship of the History and Theory of Art at the University of Stockholm 1908-1923 and was Keeper of painting and sculpture at Nationalmuseum 1928-1945. He died in Stockholm, aged 87.
In the area of Chinese art, his major books include Gardens of China, China and Gardens of Europe of the 18th century, Chinese Painting: Leading Masters and Principles, and The Walls and Gates of Peking (1924).
Sirén was an early member of the theosophist movement. In 1956, he was awarded the Charles Lang Freer Medal.