When the Newcastle & Berwick Railway received authorisation to build a railway between Gateshead and Berwick on 31st July 1845, it also gained powers to build certain branches. One such branch was the Alnmouth to Alnwick line. The company naturally concentrated on the main line and it was only after this was finished that consideration was given to the branch.
The contract for construction was let in August 1848. Progress was rapid and the line was ready to be formally opened on the 5th August 1850. The original station was constructed at the edge of the town, adjacent to Shilbottle Coal Company depot. The depot was served by a wagonway from Shilbottle Colliery - the route of which followed the present day Wagonway Road in Alnwick. The station was quite a modest affair, occupying the area now used as hard standing in front of the present day Hi-Q tyre centre, and consisted of a stone built single storey building about 60 feet long, containing offices and waiting rooms. A single platform was provided, and it is quite possible that the short section of platform that survives behind the Station Master's house dates from this time. Other buildings provided at this time included a large stone built goods warehouse and assorted stables and stores. A signal box was built at the south end of the station yard.
Services and traffic developed steadily and in 1885 Alnwick town council approached the North Eastern Railway (N.E.R.) asking for improved facilities as the existing station seemed inadequate. After initial reluctance to consider their request, the N.E.R. suddenly reversed their decision, possibly as a result of direct intervention by the Duke of Northumberland, and authorised construction of the present magnificent building. The contract for construction was let to Messers Meakin and Dean of London for £11,500 with an additional £3,931 for engineering works, a new signal box was included in the price.
Opening of the new station on 5th September 1887 coincided with the opening of the Cornhill branch which had also been constructed by the same contractor but at a cost of £272,266 15s 3d. The first train to leave the new station was a train to Cornhill headed by a Fletcher B.T.P. tank locomotive No. 199. The original station building was converted into a warehouse and an extension was built onto one end to provide stables and a mash house. This building survived until 1930 when it was demolished to provide room for a garage for the new motor parcels delivery van. Two pre-fabricated animal feed warehouses were also built on the site at this time, one of these still survives.
By the turn of the century the railway was very busy with about 60 trains a day using the station. In 1911 there were 45 passenger trains a day over the Alnwick to Alnmouth section and an additional 3 trains in each direction on the Cornhill branch. Goods traffic was very important and the 1911 returns show that 2,394 tons of building stone and 1,754 tons of grain were dispatched from Alnwick. 1,380 wagons of livestock were also loaded, which at an average load of 40 animals per wagon equates to over 45,000! This compares to total passenger ticket sales of 77,771. Incoming goods included livestock, building materials, timber, lime, coal, agricultural machinery, animal feed steel and a vast variety of sundries.
Road transport started to eat into revenue in the 1920s and particularly affected the Cornhill branch where many of the stations were a long way from the communities they were supposed to serve. All passenger services to Wooler and Cornhill were withdrawn at the end of the summer timetable in September 1930 and the number of trains to Alnmouth and beyond had fallen to 14 each way. One of these was a through train to Kelso via Berwick presumably intended to replace one of the Cornhill branch trains. Services remained at this level for the next 35 years with about half the trains being through services to either Newcastle or Berwick.
By the mid 1960s the line was said to be losing money and an attempt was made to save money by reducing the branch to single track and dispensing with all signalling equipment. The branch was worked on the one engine in steam principle and was operated from the Alnmouth end on the electric token block system, although no tokens were issued. Diesel multiple units had appeared by this time and most of the through trains to Newcastle were operated by Heaton based units. Surprisingly steam locomotives continued to work the Alnmouth trains and most of the goods trains until the 18th June 1966 when Alnmouth shed closed. The last steam passenger train was hauled by a Tyne Dock based British Railways class 9f No. 92099 which was featured on the front cover of the first issue of the Aln Valley Railway Society magazine The Link.
In March 1966 it was announced that it was proposed to close Alnwick and withdraw all services on 6th June 1966. There was a great deal of opposition to this and an appeal was made to the Ministry of Transport. However, on 28th September 1967 consent to closure was given, subject to substitute bus services being provided. Passenger services were withdrawn from 29th January 1968 but goods services lasted until 7th October that year.
Following closure, the signal boxes were demolished along with the coal depot and weigh cabins but the remaining 1850s buildings survived until 1975. At this time the goods shed was removed and re-built at Beamish Museum, County Durham.
Reasons for closure were given at the time as being purely financial, with 'creative' accounting producing a loss, but it appears that one of the deciding factors was that the Ministry of Transport realised they could substantially reduce the cost of the Alnwick by-pass, then under construction, by eliminating the need for an expensive bridge to carry the line over the deep cutting to the east of Alnwick.
Over the years a small industrial estate has been developed in the former goods yard, but this has not threatened the actual station in any way. However, a serious threat arose in 1993 when plans to develop the site as a supermarket were announced. This would have involved the demolition of all buildings on the site. It was only the timely intervention by the owners of Barter Books that prevented the development from going ahead. Owing to this threat, plans to protect the station from any future speculative development were made. This led to the formation of the Aln Valley Railway Society