Kilsyth (kɪlˈsaɪθ; Scottish Gaelic Cill Saidhe) is a town and civil parish in North Lanarkshire, roughly halfway between Glasgow and Stirling in Scotland. The estimated population is 10,380. The town is famous for the Battle of Kilsyth and the religious revivals of the 18th, 19th, and 20th centuries. The town now has links with Cumbernauld at one time being part of Cumbernauld and Kilsyth District Council. The towns also have the same members of parliament at Holyrood and Westminster.
Historically part of Stirlingshire, Kilsyth is at an elevation of above sea level and occupies a narrow strip of land between the Kilsyth Hills to the north and the River Kelvin to the south. To the east and west it is bordered by marshland and bogs. The centre of the town is close to the confluence of the Garrell and Ebroch burns.
From earliest recorded times Kilsyth was one of the main routes between Glasgow, Falkirk and Edinburgh, and is very close to the Roman Antonine Wall, the Forth and Clyde Canal and the main Glasgow to Edinburgh railway line, with the nearest railway station at Croy. Formerly two separate stations existed in the town on separate, although linked, railway lines. One, the Kelvin Valley Railway went to Glasgow-Maryhill while the other, the Kilsyth and Bonnybridge railway, went via Banknock to Falkirk. The town occupies a sheltered position in the Kelvin Valley, and is bisected by the A803 between Kirkintilloch and Falkirk. The old drovers' road from Stirling, (the Tak Ma Doon Road), and the route south to Cumbernauld via Auchinstarry Bridge, intersect the A803 at Kilsyth.
There is archaeological evidence of settlement since Neolithic times The Romans recognised the strategic significance of Kilsyth; the Antonine Wall forts of Bar Hill and Croy Hill are clearly visible from the present-day town. In the Middle Ages, Kilsyth held a key strategic position on one of the main routes across the narrowest part of Scotland. It was the site of two, now ruined, castles at Balcastle and Colzium.