Cosford Rural District was a rural district in the administrative county of West Suffolk, England.

It was created in 1894 out of the earlier Cosford rural sanitary district, except for Hadleigh parish which was made a separate urban district.

Only minor adjustments were made to its boundary in the reorganisation of 1935.

[1] It was named after the historic hundred of Cosford, although the rural district covered a significantly larger area that included most of Cosford hundred (with the notable exception of Hadleigh) and part of the neighbouring hundred of Babergh.

Since 1 April 1974 it has formed part of the local government district of Babergh.