Poensgen is a surname. Notable people with the surname include:
Ernst Poensgen (19 September 1871 in Düsseldorf – July 22, 1949, in Bern), German entrepreneur and patron of the city of Düsseldorf Erwin Poensgen (1882–1966), Ambassador of Nazi Germany to Venezuela from 1937 until 1941 Isabel Pfeiffer-Poensgen (born April 25, 1954, in Aachen), German politician Katja Poensgen (born September 23, 1976), German former professional motorcycle racer