Crathorne has been trustee of the Georgian Theatre Royal in Richmond since 1970, vice-president of the Cleveland Wildlife Trust since 1989, and patron of the Attingham Trust for the Study of the British Country House since 1990. For the Captain Cook Birthplace Museum Trust, he has been trustee since 1978 and chair since 1993. From 1988 to 1994, Crathorne was member of the National Trust of the Yorkshire Regional Committee, and, from 1992 to 1995, he was trustee of the National Heritage Memorial Fund.