Aldag is a surname. Notable people with the surname include: Bill Aldag (1905–1974), Australian rules footballer John Aldag (born 1963), Canadian politician Peter Aldag (born 1965), German sailor Roger Aldag (born 1953), Canadian football player Rolf Aldag (born 1968), German cyclist Edward K Aldag, Jr (born 1963), American Businessman, founder of Medical Properties Trust, Inc.,