Operation Diamond Racket is a 1978 Indian Kannada-language action spy thriller film produced and directed by Dorai–Bhagavan. The film stars Rajkumar, alongside Padmapriya, Chandralekha, Vajramuni, Thoogudeepa Srinivas, Tiger Prabhakar and M. B. Shetty. The music was composed by G. K. Venkatesh, while cinematography and editing were handled by P. S. Prakash and P. Bhaktavatsalam.

The film was the fourth and the final film in the CID 999 Franchise created along the lines of the James Bond and James Bond – styled films following Jedara Bale, Goa Dalli CID 999 and Operation Jackpot Nalli C.I.D 999. The film was re-released in 2013. This is the only colour film in the franchise and also the only film in the franchise to not feature Narasimharaju. It was dubbed in Hindi in 1983 as Jasoos 999. A fifth film in the franchise titled Operation Golden Gang was announced but dropped owing to average response to this movie coupled with high budget for the sequel. This was also the first film of the franchise to have a male playback singer.

The movie was shot in Nepal and became the first Kannada film to be shot outside India, but another Kannada film Singaporenalli Raja Kulla, which released four months later is widely credited as the film, which started the trend of Kannada films being shot outside India since it was shot in a country which is not an Indian neighbour.

The core plot of the film was based on Ian Fleming's novel Diamonds Are Forever where James Bond impersonates a diamond smuggler to infiltrate a smuggling ring to uncover a diamond smuggling conspiracy where his old rival wants to use the diamonds to build a space-based giant laser weapon and blackmail the world with nuclear supremacy.