Zeehan /ˈziːən/ is a town on the west coast of Tasmania, Australia 139 kilometres (86 mi) south-west of Burnie. It is part of the West Coast Council, along with the seaport Strahan and neighbouring mining towns of Rosebery and Queenstown.

The greater Zeehan area was inhabited by the indigenous Peerapper and Tommeginne clans of the North West group for over 10,000 years prior to the British colonisation of Tasmania. They were greatly coastal peoples, residing in small numbers on a diet consisting of muttonbirds, seals, swan eggs and cider gum, and constructed bark huts when strong westerly winds brought about rain and icy temperatures.

On 24 November 1642, Dutch explorer Abel Tasman became the first European explorer to sight and document the Heemskirk and West Coast Ranges. Tasman sailed his ships close to the coastal area which today encompasses the Southwest Conservation Area, south of Macquarie Harbour, but was unable to send a landing party ashore due to poor weather and did not make contact with any South West Tasmanian groups. In their circumnavigation of Tasmania between 1798 and 1799, George Bass and Matthew Flinders named the Heemskirk Ranges mountains Mount Heemskirk and Mount Zeehan after Tasman's ships, the warship Heemskerck (itself named after Jacob van Heemskerck, whose surname means "from Heemskerk") and the 200-tonne (200-long-ton; 220-short-ton) fluyt Zeehaen (Old Dutch for "Sea Rooster") in honour of Tasman's voyage of exploration. Although Dutch in origin, Bass and Flinder's Anglicised naming of Mount Heemskirk and Mount Zeehan created some of the oldest British place names in Tasmania.

Tin was discovered nearby at Mount Bischoff in 1871 and at Mount Heemskirk in 1879. Deposits of silver and lead were discovered in the area by Frank Long in 1882 and Mount Zeehan Post Office opened on 1 August 1888. The township was named Zeehan in 1890 and over the following decades, quickly expanded due to its proximity to the Zeehan mineral field. The peak period for mining was up to the First World War, when 159 companies operated at the town's peak and the town stock exchange had 60 members. With a main street over 3.2 kilometres (2.0 mi) long, the township claimed over 20 hotels, several pubs, a hospital, and two theatres, the Gaiety Theatre and Theatre Royal. It developed a friendly rivalry with Queenstown, and while the silver boom lasted it was known as the Silver City. In the first decade of the twentieth century it was the third largest town in Tasmania, after Hobart and Launceston. Sharing a mineral field and railway, the mining locality of Dundas was historically paired with Zeehan. A port was established at Trial Harbour for Zeehan, however its exposure to the Roaring Forties made the site a vulnerable anchorage. After the construction of the Strahan–Zeehan Railway, Strahan became Zeehan's favourable port. The mines earned some two hundred thousand dollars per year for two decades, before progressively declining till the 1960s, when the last mines, Montana and Oceana were closed.

The population of Zeehan-Dundas peaked at 10,000 in about 1910, over ten times the current population. In the 1970s it saw increased activity due to operations at the nearby Renison Bell tin mine, and again in the 1990s. It was the administrative centre of the Municipality of Zeehan until the early 1900s, when it merged with surrounding councils to form West Coast Council. At the 2011 census, Zeehan had a population of 728. The town was subject to several acts of arson in the 2010s, one of which saw damage to historic buildings dating back to the 1890s. The township has had its share of criminal characters-with various acts of manslaughter, assault and aggravated burglary in its history both past and present. During the COVID-19 pandemic, ten parcels of land, some as cheap as $8000, were sold by the West Coast Council as a means to attract new residents. It is hoped tourism will continue to bolster the local economy, with a new takeaway (Wildz Takeaway) open on the main road, and the creation of The Western Echo newspaper. A History of the West Coast model railway and diorama display is now open opposite the museum and is being built as a tourist attraction. The area has also seen an influx of visitors since the establishment in 2022 of several mountain biking trails around Zeehan, Trial Harbour and Queenstown.

In 2021, a study of the levels of pollution in the lakes of northwest Tasmania found a level of contamination with lead copper, cadmium and arsenic equal to the most severely polluted lakes in the world. Owen Tarn and Basin Lake near Queenstown were the worst, but Dove Lake, Lake Dobson, Lake Cygnus, and Perched Lake were also affected. These lakes are in the mountainous areas up to 130 kilometres (81 mi) downwind from Zeehan and Queenstown and have been adulterated by atmospheric pollution mainly caused by open cut mining proceeding uninhibited till finally controlled by the Environment Protection Act of 1973. Recent bushfires have caused an increase in atmospheric mercury levels to three or four times the pre-industrial level due to the release of mercury previously locked in trees. Evidence indicates the area has suffered from dangerous levels of environmental pollution for over a century.

Zeehan is connected with the north coast of Tasmania by the Murchison Highway, to Strahan by the Zeehan-Strahan Road, and Queenstown by the Zeehan Highway.

Zeehan was an important railway location—the end of the Emu Bay Railway, and the beginning of the government-owned Strahan-Zeehan Railway service that connected to Strahan and Regatta Point, where the Mount Lyell Railway connected to Queenstown. Also at early stages of the town's history, a series of timber trams spread out from Zeehan towards the Pieman River as well as a number of other locations.