Joyce Mildred Lambert (23 June 1916 – 4 May 2005) was a British botanist and ecologist.
She confirmed by stratigraphic sampling the theory of Clifford Smith that the Norfolk Broads were of man-made origin, the result of extensive peat-digging, and not a natural formation as the geomorphologist Joseph Newell Jennings had recently concluded.
She collaborated with Jennings and Smith on a further study of the Broads; their results were published in 1960 as The Making of the Broads: a reconsideration of their origin in the light of new evidence.