Helensburgh (; Scottish Gaelic: Baile Eilidh, lit. ‘town (or burgh) of Helen’) is a town within the Helensburgh and Lomond Area of Argyll and Bute Council, Scotland. It also has its own Community Council. Until local government reorganisation in 1996 Helensburgh was in Dumbarton District and hence also in Strathclyde Region; prior to 1975 it was a small burgh with its own town council within Dunbartonshire.
In the Middle Ages it was within the Earldom of Lennox, an area sometimes referred to as the Lennox. It lies on the north shore of the Firth of Clyde and the mouth of the Gareloch is close to the western boundary of the town.