The Welland River is a river in the Niagara Region of southern Ontario which flows from its headwaters south of Hamilton, Ontario to empty into the Niagara River near the city of Niagara Falls, Ontario. It drains an area of 880 square kilometres (340 sq mi).
The river was originally called the Chippawa Creek since it drained into Niagara River at Chippawa. Like many other places in Niagara, it was renamed by John Graves Simcoe, the first lieutenant governor of Upper Canada in 1792. The present name is taken from River Welland in Lincolnshire in eastern England. The river is still occasionally referred to as Chippawa Creek, especially by those in the Chippawa area itself.
The Welland Canal was named after the river since it originally was planned to link Lake Ontario to Welland River. The city of Welland, Ontario was later named after both waterways, which cross in the city.
The river flows under two navigable aqueducts: the Welland Recreational Waterway and the new alignment of the Welland Canal. An important tributary of the river is Coyle Creek, a picturesque and thickly forested creek that flows into the river on the north bank. The oldest structure spanning the river was O'Reilly's Bridge, which was built in 1901 and crossed the river between the townships of Pelham and Wainfleet. The settler, Patrick O'Reilly, son of Sgt. John Reilly, of Stamford Township, settled in Wainfleet in 1806. After Meeting the daughter, Sarah, of John Brown of Pelham Township Patrick O'Reilly felled a couple of very tall trees across the River to shorten his journey to see her. A better bridge was built after they married and Patrick realized Sarah was frightened of walking along the logs. John Brown O'Reilly was their son who acted as Clerk of Wainfleet Township for many years. Over the years O'Reilly's Bridge saw many upgrades and improvements until it finally became the responsibility of the municipality.That's about the time O'Reilly's Bridge became a single-lane iron truss bridge, the only of its kind on the entire river, and one of the oldest iron truss bridges in Southern Ontario. O'Reilly's Bridge was demolished in 2010 and was replaced with a more modern, wider span.
Hydroelectric generation activities in the Niagara Falls region actually cause the flow in the lower section of this river to reverse, as seen in this satellite picture.