NGC 1751 (also ESO 56-SC23 and GC 971) is a magnitude +14.5 open star cluster located in the constellation Mensa.
The cluster was discovered by Scottish astronomer James Dunlop using a homemade 9-foot 22.86 cm (9 inch) f/12 speculum Newtonian reflector at Paramatta, New South Wales, Australia, on the 24th September 1826. The cluster was rediscovered by John Herschel in November 1836.
Right Ascension 04h 54m 12.1s, Declination -69° 48' 23"