The Blackburn R.B.2 Sydney (serial N241) was a long-range maritime patrol flying boat developed for the Royal Air Force in 1930, in response to Air Ministry Specification R.5/27. It was a parasol-winged braced monoplane of typical flying boat arrangement with triple tailfins and its three engines arranged on the wing's leading edge. After evaluation, it was not ordered into production and no further examples were built.
With development of the Sydney abandoned, construction of a cargo-carrying variant powered by radial engines, the C.B.2 Nile was also ended.