Diamond Queen is a 1940 Hindi action adventure comedy film. It was directed by Homi Wadia and produced by Wadia Movietone. It starred Fearless Nadia, John Cawas, Radha Rani, Sayani Atish, Sardar Mansur, Dalpat, Kunjru, and Boman Shroff. This film was the seventh in the Diamond thriller series with the first being Veer Bharat in 1934, directed by Homi Wadia under the production of J. B. H. Wadia. It is cited as one of the best films produced by the Wadia brothers. The film's success saw Homi Wadia becoming a producer by which he was able to obtain raw stock for his films due to the rationing of two films per producer during the Second World War.

Homi Wadia was an Indian film director and producer in Bollywood. He was the co-founder of Wadia Movietone productions, established in 1933 and later after the closure of Wadiatone, he founded Basant Pictures in 1942. In a career spanning five decades, he directed over 40 films, including Hunterwali (1935), Miss Frontier Mail (1936), Diamond Queen (1940), Shri Ram Bhakta Hanuman (1948) and fantasy film Hatim Tai (1956). He was also a founding member of the Film & Television Producers Guild of India, established in 1954. Homi Wadia was married to actress and stunt woman Fearless Nadia. Homi was the younger brother of JBH Wadia, who was himself a movie director.