Wisbech castle is believed to have been a motte-and-bailey castle earthwork castle built to fortify Wisbech, in the Fenland area of Cambridgeshire, England on the orders of William I in 1072. This was probably oval in shape and size as on the line still marked by the Crescent . The Norman castle, reputedly was destroyed during a devastating flood of 1236, the original design and layout is still unknown. It was rebuilt in stone in 1087. In the 15th century repairs were becoming too much for the ageing structure, and it was decided to create a new building, starting in 1478 under John Morton Bishop of Ely (later Archbishop of Canterbury and Chancellor of England). His successor, John Alcock, extended and completed the re-building and died in the Castle in 1500. Subsequent bishops also spent considerable sums on this new palace. The Bishop's Palace was built of brick with dressings of Ketton Stone, but its exact location is unknown.
In later Tudor times the rebuilt castle became a notorious prison. The site was again redeveloped in the mid-17th century and yet again in 1816 by Joseph Medworth. A 1794 plan of the 'castle' exists, this only shows the 'castle' as it existed at the end of the 18th century, prior to the development of the site to its current form.
The castle and town of Wisbech were swept away in a storm in 1236. In 1315 Richard Lambert of Lenne (Lynn), Merchant brought an action against William le Blowere and others for a conspiracy to imprison him. He had been "thrown in the depth of the gaol of Wysebech among thieves, where by toads and other venomous vermin he was so inhumanely gnawed that his life was despaired of". In 1350 John de Walton was lodged in the castle accused of trespass and rebellion. 
From 1478-83 the Bishop's palace was constructed of bricks measuring 11 inches in length and 2.5 inches thick with dressing of Ketton stone. The property's cellars and foundations can still be seen. The palace was extended by Bishop Alcock.
During the reign of Queen Mary (1553-1558) Protestants were imprisoned here during her pursuit of the restoration of Roman Catholicism in England and Ireland.
Queen Elizabeth I passed into law the Act of Uniformity 1558. In 1572 the Privy council asked the bishop to report on the suitability of the castle for holding papists. In 1580 the bishop was enjoined to put the castle 'in order and strength' to receive prisoners and the first were received in October. In 1583 a prisoner Dr Andrew Oxenbridge is recorded as taking the oath of supremacy. In 1584 it was suggested that the number of prisoners be limited to twenty.
In the last years of the 16th century there were 33 Catholics held prisoner in Wisbech Castle, almost all of them priests, including the Jesuit priests, Christopher Holywood, William Weston and lay brother Thomas Pounde. A quarrel arose among them that came to be known as the "Wisbech Stirs". In the winter of 1594-95 a substantial group (18 of the 33) wished to separate themselves from the rest and adopt a regular communal life. This was largely impossible without appearing to castigate those who did not want to make this change and on account of the limited space. The unwilling minority argued, which only confirmed the others in their resolve, and the separation was carried out in February 1595, but came to an end with a general reconciliation in November of that same year. Philip Strangeways was one of the missionary priests imprisoned at Wisbech at the end of Elizabeth's reign.
Other leading Roman Catholics were imprisoned for political reasons, at the time of the Spanish Armada; Robert Catesby and Francis Tresham were also held at Wisbech. Later they were to become the principal conspirators in the Gunpowder Plot.
In 1616 a priest Thomas Tunstal escaped from the castle to Norfolk, Sir Hamon L'Estrange had him pursued and apprehended. He was tried at Norwich and condemned and executed. The use of the castle for recusant prisoners ceased in 1627.
During the English Civil War the Castle was re-fortified with outposts at the Horseshoe Sluice & Leverington. In 1643 the castle was used to secure the river Nene frontier and block any attempt from the Newark garrison to relieve the besieged King's Lynn Royalists. The castle was armed with cannon 'Great Guns' from Ely and money from the town to pay for ironwork to repair the drawbridge. The garrison at Wisbech was commanded by Lt Col Dodson and carried out skirmishing in the surrounding Fenland. The naval blockade, siege and bombardment brought capitulation from the King's Lynn after three weeks. Peterborough was occupied by the Parliamfntarians before the capture of Crowland. Sir John Palgrave commanded a Norfolk regiment at this time stationed at Wisbech. His second in command was Sir Edward Askey. In July Torrell Jocelyn wrote to the Speaker expressing the concerns the town's residents had about the behaviour of their men and his hope that the recently arrived regiment led by Sir John Holland would do better. Captain Thomas Pigge of Walsoken was taken prisoner by the Earl of Essex in October 1634 and exchanged at Burghley House 'on a bond of £2,000 never to bear arms again'.
An Act of 1793, 33 Geo.III.,..53 empowered the Bishop of Ely to sell the castle. James Lord, bishop of Ely put up the castle for auction in 6 lots at the Rainbow coffee house, Cornhill, London on Wednesday, 13 November 1793. Joseph Medworth as the highest bidder for all six lots totalling £2,305.
The present Regency villa formed the centre of a major redevelopment of the area in 1816, ensuring that the site has been continuously inhabited for nearly a thousand years.
Mr and Mrs Gordon Fendick bought the property and, in the 1960s, passed ownership to Isle of Ely County Council this became the Cambridgeshire and Isle of Ely County Council, then Cambridgeshire County Council. The Castle was used as a Professional Development Centre, providing a venue for meetings and training. School visits took place and the property is licensed for Civil Weddings. It has been registered as an asset of community value. In February 2018, Wisbech Town council took over the running of the site. The Wisbech Castle Project is run by a Castle Management Committee of Wisbech Town Council and a Castle Working Party of councillors, volunteers and local experts.
In recent years The Castle has been used as a location for television and film drama. The BBC's David Copperfield and Atlantic Films, Dean Spanley both utilised the building and the Crescent for parts of their productions.
In September 2009 excavations were carried out on the site by Oxford Archaeology East and local volunteers. The report was published July 2010. The Wisbech Castle Community Archaeology Project was 'Highly Commended' in the Best Community Archaeology Project category at the 2010 British Archaeological Awards. As a result of the dig local volunteers formed a local archaeology group – the Wisbech and District Archaeology Society (WADAS) - now FenArch (Fenland Archaeological Society); initially meeting at The Castle before moving to Mendi's restaurant on the Old Market.
- *Mike Osborne (2013). Defending Cambridgeshire. The History Press.
- ed WD Sweeting. Fenland Notes & Queries, vol 4.
- Wisbech Society (1975). 36th Annual Report.
- Mike Osborne (2013). Defending Cambridgeshire: The military landscape from prehistory to the past. The History Press.
- Sweeting, Walter Debenham (1900). Fenland Notes & Queries Vol IV.
- Polle 1909.
- Farrer & Brownbill 1911, pp. 259–262 cites Misc. (Cath. Rec. Soc.), i, 110; ii, 278, &c.
- R.W. Ketton-Cremer (1969). Norfolk in the civil war. Faber & Faber.
- Atkinson 2002, pp. 252-253.
- Mike Osborn (2013). Defending Cambridgeshire. The History Press.
- Mike Osborne (2013). Defending Cambridgeshire.
- R.W Ketton-Cramer (1969). Norfolk in the civil war. Faber & Faber.
- The life of John Thurloe Esq., Secretary of State, published in: A Collection of the State Papers of John Thurloe, Volume 1, 1638-1653, ed. Thomas Birch (London, 1742), pp. xi-xx. 
- ed Rev.W.D.Sweeting (1900). Fenland Notes & Queries vol IV.
- CCC 2010.
- Fenland District Council.
- Reynold, P (1958), The Wisbech Stirs, London
- Anniss, G (1977), A history of Wisbech castle
- Atkinson, T D; et al. (2002), "Wisbech: Recusants in the castle", in Pugh, R.B., A History of the County of Cambridge and the Isle of Ely, Volume 4, City of Ely; Ely, N. and S. Witchford and Wisbech Hundreds, London: Victoria County History, pp. 252–253
- "Welcome to Wisbech Castle", Wisbech Castle (Cambridgeshire County Council), 2010, archived from the original on 4 March 2016
- Farrer, William; Brownbill, J., eds. (1911), "Townships: Cheetham", A History of the County of Lancaster, 4, London, pp. 259–262