South Western Railway is a train company in England.

South Western Railway or Southwestern Railroad (or similar) may also refer to:

• South West Rail Link in Sydney, Australia
• South Western railway line, Queensland, Australia
• South Western Railway, Western Australia

• Glasgow and South Western Railway in Scotland
• London and South Western Railway in England
• South West Main Line in England

• Southwestern Railroad (Georgia), predecessor of the Central of Georgia Railway
• Southwestern Railroad (Kentucky), predecessor of the Southern Railway (1876-1889)
• Southwestern Railroad (New Mexico), presently operating
• Southwestern Railroad (Tennessee), predecessor of the Nashville, Chattanooga and St. Louis Railway (1852-1877)

• Southwestern Railways in Ukraine
• South Western Railway (South Africa)
• South Western Railway zone in India

• South and Western Railway, see Clinchfield Railroad
• South West Trains, formerly South Western Railway (UK)