Archaeological finds indicate that the area has been settled for more than 4,000 years.
The modern town was founded as New or Nye-Sukkertoppen in 1782 by Danish colonists relocating from the original Sukkertoppen, a trading post founded in 1755 at the site of present-day Kangaamiut. In time, the original name was taken up again.
In the 19th century, the town served as a major trading post for the Royal Greenland Trading Department's trade in reindeer hides.
Maniitsoq Municipality was a former municipality of Greenland. It is now part of Qeqqata Municipality.
There are advanced plans for an Alcoa aluminium smelting plant either at Maniitsoq or Sisimiut. The plant would provide employment for 600–700 people, or more than 1 percent of the population of Greenland. As it is a vital decision for the town, wide public consultations were carried out in 2008–2010 by both the town authorities and the Greenland Home Rule Government in order to address potential environmental and social concerns.
Maniitsoq is served by Air Greenland with flights to Nuuk, Kangerlussuaq, and Sisimiut.
Maniitsoq is a port of call for the Arctic Umiaq ferry.
With 2,670 inhabitants as of 2013, Maniitsoq has experienced a decline in population over a long period of time. The town has lost almost 15% of its population relative to 1990 levels, and nearly 9% relative to 2000 levels.
Migrants from the smaller settlements such as rapidly depopulating Kangaamiut choose to migrate to Sisimiut, the capital in Nuuk, and sometimes to Denmark, rather than Maniitsoq. Kangerlussuaq and Sisimiut are the only settlement in the Qeqqata municipality exhibiting stable growth patterns over the last two decades.
A 100 km (62 mi) wide circular region with unusual geological features is believed to be the results of a massive asteroid or comet impact about three billion years ago. The region is centered about 55 km (34 mi) south-east of Maniitsoq at coordinates 65°15′N 51°50′W / 65.250°N 51.833°W / 65.250; -51.833 (Maniitsoq).
During the 3 billion years following the impact, the crater has eroded down, and the features now exposed were buried 20 to 25 km (12 to 16 mi) below the surface at the time the event occurred. This erosion processes is the reason that very few remaining craters are visible on Earth.
According to a study published in 2012, scientist believe that it is an impact crater created by a single event involving intense crushing and heating, rather than a deformation in the earth's crust formed by the interaction of tectonic plates. According to the study, the inferred scale, strain rates and temperatures necessary to create the Maniitsoq structure rule out a terrestrial origin.
More research is needed before the Maniitsoq structure can be definitely confirmed as an impact crater because present diagnostic tools used to identify impacting in the upper crust are inadequate for giant, deeply eroded structures. If confirmed as an impact crater, this crater would be older than other old impact craters such as the much smaller 16 km (10 mi) wide, 2.4 billion year old, Suavjärvi crater in Russia and the larger 300 km (186 mi) wide, 2.0 billion year old, Vredefort crater in South Africa.
The 2012 study was published by scientists from the Geological Survey of Denmark and Greenland (GEUS), along with members from Cardiff University, Lund University in Sweden, and the Institute of Planetary Science in Moscow.
Maniitsoq is twinned with: