The 100-Series Highways are a series of arterial highways in the Canadian province of Nova Scotia. A 100-series highway is a designation applied to a highway that can be a controlled-access expressway, Super-2, or fully divided freeway. The designation can also be applied in some cases to sections of uncontrolled access roads which are deemed strategically important and which will be upgraded in the future to controlled-access. Some of the 100-series highways also carry the Trans-Canada Highway designation on their routes.