NGC 3172 (also known as Polarissima Borealis) is a lenticular galaxy located in the constellation Ursa Minor. It is the closest NGC object to the north celestial pole. Discovered by John Herschel in 1831, it is about 285 million light-years away and about 85 thousand light-years across.

Two supernovae have been observed in NGC 3172. SN 2010af (type Ia, mag. 17.2), was discovered on 4 March, 2010. SN 2017gla (type Ia, mag. 16), was discovered on 1 September, 2017.

See also

• NGC 2573 - the closest NGC object to the south celestial pole.