The River Ness (Scottish Gaelic: Abhainn Nis) is a short river in the Great Glen of Scotland. It begins at Loch Dochfour, at the northern end of Loch Ness, and flows northeast towards the city of Inverness, where it empties into the Moray Firth. It runs parallel to the Caledonian Canal for the first half of its course, which is six miles (10 km) long in total.

At Inverness, the river contains a group of wooded islets known as the Ness Islands, some of which are linked to the shore by footbridges.

There has been a bridge over the Ness at Inverness since at least the 15th century. The bridge was originally made of timber, but it was rebuilt in stone in 1685. The 1685 bridge endured until 1849, when it was swept away in a flood. J. M. W. Turner painted it before its destruction. The suspension bridge built to replace the bridge of 1685 was itself replaced in 1961 by the present Ness Bridge, a concrete structure. Other noteworthy bridges over the Ness are the Greig Street Bridge and the Infirmary Bridge, two Victorian suspension bridges.

The first claimed sighting of the Loch Ness Monster was in the River Ness in AD 565, when Saint Columba is said to have banished a "water monster" back into the river after it tried to attack one of his disciples who was swimming across the river.

According to Adomnán, when Columba visited King Bridei I of Pictland at his house on the River Ness, he met a wizard named Broichan who had an Irish slave-girl that he refused to release even though Columba pleaded with him. Columba went out of Bridei's house and picked up a white pebble from the river. He said that the pebble would be used to heal many sick people in Pictland, and that Broichan was suffering for his sins at that very moment. After he had finished speaking, two messengers came to tell them that Broichan had a seizure and they wanted Columba to help them. Columba gave them the stone and said to dip it in water to give to Broichan, if he agreed to release the slave-girl. He agreed to do so, and the stone was put in water and it floated on it; the wizard drank from the water and was healed. This stone was kept by King Bridei in the royal treasury for the rest of his life, and anyone who came there for healing would be given water with the stone floating in it, and they would be healed.

• Rivers of Scotland