North–South line may refer to any of several different railway and metro lines:
- North-South Line (KTM Intercity), the West Coast Line in Malaysia
- North–South MRT line, in Singapore
- North–South Line (Jakarta MRT), in Indonesia
- North/South line (Amsterdam metro), in the Netherlands
- NS Line, in Portland, Oregon, U.S.
- Red Line (MARTA) (formerly North–South line) in Georgia, U.S.
- South Line, Tasmania, sometimes the North–South Line, in Tasmania
- North–South Rail Link, in Boston, Massachusetts, U.S.
- North–South line (Saudi Arabia), in Saudi Arabia
- Sydney Metro Western Sydney Airport, Stage 1 of a proposed North South Rail Line, in Sydney, Australia
- North–South connection, in Brussels, Belgium
- North–South Junction, in Wellington, New Zealand
Namboku Line (南北線, Nanboku-sen, 'South North Line') may refer to any of several Japanese railway lines: