Guildford railway station is an important railway junction on the Portsmouth Direct Line serving the town of Guildford.

The station was opened by the London and South Western Railway (LSWR) on 5 May 1845, but was substantially enlarged and rebuilt in 1880. The Reading, Guildford and Reigate Railway opened its services on 4 July 1849, and was operated by the South Eastern Railway. LSWR services to Farnham via Tongham began on 8 October 1849 and the New Guildford Line to Leatherhead and Epsom Downs on 2 February 1885.

On the latter line is the other Guildford station: London Road: the line to it describes a curve around the town on an embankment, crossing the River Wey by a high bridge. Guildford station was also the northern terminus of the (now-closed) Cranleigh Line of the London Brighton and South Coast Railway, which opened 2 October 1865 and closed almost one hundred years later on 12 June 1965. This line ran to Horsham by way of Cranleigh, Rudgwick and Christ's Hospital. The station is currently served by services operated by First Great Western from Reading to Gatwick Airport and South West Trains from London Waterloo to Portsmouth Harbour, Waterloo to Guildford via Cobham or Epsom and Ascot to Guildford via Aldershot. Occasional CrossCountry trains to Newcastle and Southern services on the Sutton and Mole Valley route towards West Croydon & London Bridge also calls.

Guildford station is to be the southern terminus for the proposed Heathrow Airtrack rail service. This project, promoted by BAA, envisages the construction of a spur from the Waterloo to Reading Line to Heathrow Airport, creating direct rail links from the airport to Guildford , Waterloo, Woking and Reading. Airtrack is planned to open in 2015, subject to government approval.