Ittefaq (English: Coincidence) is a 1969 Indian mystery thriller film produced by B. R. Chopra and directed by his brother Yash Chopra. The film stars Nanda and Rajesh Khanna in the lead with Sujit Kumar, Bindu, Madan Puri and Iftekhar playing supporting roles and has music by Salil Chowdhury. It is based on the 1965 American film Signpost to Murder (an adaptation of a 1962 play of the same name by Monte Doyle), which had earlier been remade into a Gujarati play Dhummas starring Sarita Joshi.

It was the fourth Bollywood film (after Naujawan, Munna and Kanoon) that did not have any songs in it. What was remarkable was that a previous production from the same production house, i.e. B. R. Films, namely Kanoon, made in 1960, was also a song-less film and with the same leading lady Nanda. Another common feature of both Kanoon and Ittefaq was that in both these song-less films Salil Chowdhary was the music director. This was also the first Hindi film that did not have any interval.

This film is counted among the 17 consecutive hit films starring Rajesh Khanna in a lead role between 1969 and 1971, by including the two multi-starrer films Marayada and Andaz to the 15 consecutive solo hits he gave from 1969 to 1971. This is also the last film Yash Chopra would direct for his brother before branching out to form his own production company Yash Raj Films.