St Cosmas and St Damian Church is an Anglican church in the village of Keymer, in the Mid Sussex district of West Sussex, England. Rebuilt in 1866 in a style similar to the Saxon building it replaced, it is the parish church of Keymer and now lies within a combined parish serving three villages in Mid Sussex. The church bears a very rare dedication to the twin Saints Cosmas and Damian, Christian martyrs of the 4th century.