Diana Spencer (1961–1997), later Diana, Princess of Wales, was the first wife of King Charles III.
Diana Spencer may also refer to:
- Diana Spencer (classicist) (born 1969), professor of classics
- Diana Spencer (diver) (born 1934), British Olympic diver
- Lady Diana Beauclerk (née Lady Diana Spencer, 1734–1808), English noblewoman and artist
- Diana Russell, Duchess of Bedford (née Lady Diana Spencer, 1710–1735), wife of John Russell, 4th Duke of Bedford