Swindon railway station is on the Great Western Main Line in South West England, serving the town of Swindon, Wiltshire. The station is 77 miles 23 chains (77.29 mi; 124.4 km) down the line from the zero point at London Paddington and lies between Didcot Parkway and Chippenham. It is managed by Great Western Railway, which also operates all of the services from the station. It is the busiest station in Wiltshire, and the third busiest station in South West England.

Being roughly halfway between the English and Welsh capitals of London and Cardiff, it is an important junction where the former Great Western Railway line to Gloucester and Cheltenham Spa, the main line to Bristol Temple Meads, and the South Wales Main Line via Bristol Parkway diverge.

The station is sited approximately 220 yards (200 metres) from the central bus station and the town centre. It is served by GWR services from Paddington to Bristol Temple Meads; Cheltenham Spa via Gloucester; Cardiff Central, Swansea and the rest of South Wales; and to Westbury.

The main line of the Great Western Railway (GWR) was built and opened in stages. Construction began in late 1835, and by the end of August 1840 the line was open between Paddington and Faringdon Road (later known as Challow), also between Bristol and Bath. The section from Faringdon Road to a temporary terminus at Hay Lane (near Wootton Bassett) was opened on 17 December 1840; this passed to the north of the market town of Swindon (now known as Old Town); but the only intermediate station opened at that time was at Shrivenham.

Meanwhile, the Cheltenham and Great Western Union Railway had in 1836 been authorised to link the GWR with Gloucester and Cheltenham, and for this line, a junction at Swindon had been decided upon. The GWR line was planned by Isambard Kingdom Brunel to rise from both London and Bristol to a summit near Swindon, and to have easy gradients east of that summit, and steeper gradients to the west. Brunel, and his colleague Daniel Gooch, decided in October 1840 that one locomotive would not be able to manage the whole distance without taking on fuel; and it would be necessary to change locomotives part-way. Reading was chosen as one place to change engines, being both a major station and, at just under 36 miles (58 kilometres), approximately one-third of the 118-mile (190-kilometre) distance from Paddington to Bristol. They also felt that it would be convenient to change locomotives at Swindon; not only was this almost two-thirds of the way (just over 77 mi or 124 km) and the site of the junction for the Cheltenham line, it was also the summit of the line; and a train from London could have its fast locomotive replaced by a slower but more powerful locomotive for the journey on to Bristol. Accordingly, it was necessary to provide locomotive maintenance facilities at Swindon.

The proximity of the North Wilts Canal was also a factor, since it would enable coke for the locomotives and coal for the workshops to be supplied from the Somerset Coalfield at a reasonable price. A station was then planned around the junction, and opened at the same time as the first portion of the Cheltenham line (from Swindon to Kemble and Cirencester); the GWR main line was extended from Hay Lane to Chippenham on the same day, 31 May 1841. The GWR had engaged the Westminster firm of Messrs. J. & C. Rigby to build several stations, including all those between Steventon and Corsham; this firm was also given the construction contracts for all of the buildings at Swindon, including the station and its refreshment rooms, the locomotive repair shops, 300 houses and other buildings needed for the workers. The GWR was short of money, and in late 1841 the contractors, instead of asking for payment, agreed to give Swindon station and its refreshment rooms to the GWR free of charge, and to lease back the refreshment rooms for 99 years at one (old) penny per year. Part of the deal was that

All trains carrying passengers, not being Goods trains or trains to be sent express or for special purposes, and except trains not under the control of the Great Western Railway Company, which shall pass the Swindon Station either up or down, shall, save in case of emergency or unusual delay arising from accidents, stop there for refreshment of passengers for a reasonable period of about ten minutes.

In this "reasonable period", not only could the passengers be refreshed but the locomotive would also be changed. Messrs. Rigby would then be able to use the profits from the refreshment rooms to recover their financial outlay. Not long after the contract was finalised, Rigby then sublet the rights to S. Y. Griffiths of Cheltenham for seven years, for which Griffiths paid Rigby £6,000 up front and then £1,100 per year. Before this expired, Rigby sold the lease to J. R. Phillips for £20,000 in August 1848.