David Mervyn Johns (Pembroke, Gal·les, 18 de febrer de 1899 - Northwood, Londres, 6 de setembre de 1992) va ser un actor d'escenari, cinema i televisió gal·lès que es va convertir en una estrella del cinema britànic durant la Segona Guerra Mundial. Era el pare de l'actriu Glynis Johns.

Father of actress Glynis Johns, who appeared with him in The Halfway House (1944) and The Sundowners (1960). Stocky, benevolent-looking Welsh character who became an unexpected star of British movies during WWII, then moved quickly into post-war supports, with one of his fondly-remembered parts being that of the cowering "Bob Cratchit" to Alastair Sim's cold-hearted "Ebenezer Scrooge" in the definitive film version of A Christmas Carol (1951).