M?ori had lived in Greymouth for considerable time before European settlement, and called the area Mawhera (for 'wide spread river mouth', still an alternative name for the Grey River). The first European to visit the site of what is now Greymouth was Thomas Brunner in 1846. Brunner discovered coal in the Grey valley, and several places in the region (notably the town of Brunner and Lake Brunner) bear his name. Brunner himself named the Grey River after prominent 19th century New Zealand politician Sir George Grey. Together with gold, coal mining was a major impetus in the town's early European history.
From 1853 until the abolition of provinces in 1876, Greymouth was first part of Canterbury Province (the West Coast part of the Province was known as West Canterbury) and then part of an independent Westland Province. However Cobden, on the north (or right) bank of the Grey River was a part of Nelson Province from 1853 to 1876. At one point in this period Greymouth tried to join Nelson Province but this movement was ultimately unsuccessful.
Greymouth has a history of coal and gold mining. When the mining industry started to decline, forestry became a new staple industry. Fishing has long been important to the town, despite the fact that the entrance to the Grey River has two notoriously dangerous sandbars; an inner and outer bar.
Greymouth also has an historic World War II gun emplacement at Cobden. The Grey District Council destroyed part of this site, without consultation, in 2007 to make way for a sewer line.
On 10 March 2005, a major tornado, which started as a waterspout, made landfall in Blaketown, a suburb of Greymouth. It quickly moved through the town passing just south of the main town centre. The tornado was one of the largest reported in recent history in the West Coast region and caused millions of dollars in damage and injured several people.
On 19 November 2010, there was an explosion at the Pike River Mine, trapping
