Northwest Line or North West Line or North-West Railway or similar may refer to:
Asia North-West Railway, official name of Light Rail (MTR), Hong Kong
Europe Northwest railway line, Austria and Czech Republic Northwest Line (Denmark)
North America Northwest Line (C-Train), Calgary, Canada Northwest Rail Line, name used during construction of the B Line (RTD), Denver, United States Union Pacific Northwest Line, Metra commuter rail line, United States
Oceania Metro North West & Bankstown Line, Sydney, Australia Sydney Metro Northwest, the associated construction project
See also Northwest Corridor (disambiguation)