The River Irvine () is a river that flows through southwest Scotland. Its watershed is on the Lanarkshire border of Ayrshire at an altitude of above sea-level, near Loudoun Hill, Drumclog, and SW by W of Strathaven. It flows westward, dividing the old district of Cunninghame from that of Kyle, until it reaches the sea via Irvine Harbour in the form of the Firth of Clyde, and flows into Irvine Bay by the town of Irvine. It has many tributaries, some of which form parish, district and other boundaries.