Carnforth station was opened in 1846 by the Lancaster and Carlisle Railway Company (LCRC). It originally had a single platform, but it became a junction in 1857 when it became the terminus of the Ulverston & Lancaster Railway. This later became part of the Furness Railway.

In 1867 the Midland Railway arrived from the east. Meanwhile, the LCRC had been taken over by the London & North Western Railway Company (LNWR) and Carnforth came under joint management by the Furness, Midland and LNWR. Station personnel wore a uniform with the initials CJS for Carnforth: Joint Station.

It thus became an important junction with trains for Leeds and Barrow as well as the west coast main line. When the original main line platforms were closed, the station declined. It was revived in 2003 and became a railway centre with a model shop, book shop and permanent exhibition around the set of the film 'Brief Encounter'. The refreshment room has been restored and serves its original function.

At the end of the Furness platform there is an unusual little signal box, built in about 1870 and listed Grade II. It has a tall circular chimney in Tudor style at one end with a roundel for a clock. At the other end are the arms of the Furness Railway.

A major rebuilding project, including a new 300 yard platform, took place in 1938 with government funding. The West Coast Main Line platforms were closed in May 1970. The platform walls facing the fast lines were demolished, bartered back and fenced off a few years later prior to electrification. This effectively made Carnforth a branch line station, even though it is situated on the main line, as WCML trains cannot now call here. The station fell into dereliction from the 1960s. The Carnforth Station and Railway Trust Company was formed in 1996 to restore the buildings. A £1.5 million project was commenced in late 2000 in cooperation with Railtrack, and after three years work, the Brief Encounter Refreshment Room and Visitor Centre was opened on 17th October 2003.  

David Lean filmed his romatic classic, "Brief Encounter", at Carnforth Station during February 1945; filming had to take place at night between 10pm and 6am so as not to interfere with daytime train operations. The station clock became a powerful icon through repeated use in the film.