South Line
- Glasgow South Western Line
- Main South Line
- Main Southern railway line, New South Wales
- North–South line (disambiguation)
- PNR South Main Line
- Sounder South Line
- South Eastern Main Line
- South Line, Chennai Suburban
- South Line, Tasmania
- South West Line, Chennai Suburban
- South West Main Line
- South Western Line (disambiguation)
- South-Link Line
- Southern Line (disambiguation)
- Southern Railway (disambiguation)
- West South Line, Chennai Suburban
- Østfold Line