Portneuf is a municipality in the Portneuf Regional County Municipality, in the province of Quebec, Canada. It is located on the Saint Lawrence River, between Quebec City and Trois-Rivières. The Portneuf River runs on the east side of the town centre.The town of Portneuf is named after a seignory that was founded in 1636, and first settled in 1640.The municipal territory consists of 2 non-contiguous areas, separated by the municipality of Sainte-Christine-d'Auvergne. The smaller northern portion is undeveloped, whereas the southern piece is the main inhabited part with the population centres of Portneuf (south of Autoroute 40), and the adjacent Notre-Dame-de-Portneuf, north of A-40. The present-day municipality was created in 2002, when the old city of Portneuf merged with the town of Notre-Dame-de-Portneuf.The town is located on the Chemin du Roy, a historic segment of Quebec Route 138 that stretches from near Montreal to Quebec City. The town is also close by to A-40, where Provencher Street connects to the town at Exit 261.One of Portneuf's major employers is a local paper mill owned by Metro Paper Industries, a Toronto-based paper company. Paper had been a major part of Portneuf's development since the first paper mill opened in 1839.