The Blue Diamonds were a Dutch 1960s rock and roll duo, best known for their million-selling chart-topping single, "Ramona". Indo (Dutch-Indonesian) brothers Ruud de Wolff (12 May 1941 – 18 December 2000) and Riem de Wolff (born 15 April 1943) founded the group shortly after immigrating to the Netherlands in 1949. They were born in Batavia (now Jakarta), Indonesia.

Called the 'Dutch Everly Brothers', The Blue Diamonds covered many Everly Brothers songs, but became famous in 1960 with their version of "Ramona", a song originally written for the 1928 film, Ramona. The song was written for promotional appearances with Dolores del Río (star of the film) but not featured in the film itself. The Blue Diamonds up-tempo version of it reached the American Billboard Hot 100 at #72 in 1960. It sold over 250,000 copies in the Netherlands (the first record to ever do so) and over one million copies in Germany by 1961.