Lacock Abbey in the village of Lacock, Wiltshire, England, was founded in the early 13th century by Ela, Countess of Salisbury, as a nunnery of the Augustinian order. The abbey remained a nunnery until the Dissolution of the monasteries in the 16th century; it was then sold to Sir William Sharington who converted the convent into a residence where he and his family lived. It was fortified and remained loyal to the crown during the English Civil War, but surrendered to the Parliamentary forces once Devizes had fallen in 1645.

The house was built over the old cloisters and its main rooms are on the first floor. It is a stone house with stone slated roofs, twisted chimney stacks and mullioned windows. Throughout the life of the building, many architectural alterations, additions, and renovations have occurred so that the house is a mish-mash of different periods and styles. The Tudor stable courtyard to the north of the house has retained many of its original features including the brewhouse and bakehouse.

The house later passed into the hands of the Talbot family, and during the 19th century was the residence of William Henry Fox Talbot. In 1835 he made what may be the earliest surviving photographic camera negative, an image of one of the windows.

In 1944 artist Matilda Theresa Talbot gave the house and the surrounding village of Lacock to the National Trust. The abbey houses the Fox Talbot Museum, devoted to the pioneering work of William Talbot in the field of photography. The Trust markets the abbey and village together as "Lacock Abbey, Fox Talbot Museum & Village". The abbey is a Grade I listed building, having been so designated on 20 December 1960.

Lacock Abbey, dedicated to St Mary and St Bernard, was founded in 1232 by Ela, Countess of Salisbury, widow of William Longespee, an illegitimate son of Henry II. Ela laid the abbey's first stone in Snail's Meadow, near the village of Lacock on 16 April 1232. The first of the Augustinian nuns were veiled in 1232, and Ela joined the community in 1238.

Lacock Abbey prospered throughout the Middle Ages. The rich farmlands which it had received from Ela ensured it a sizeable income from wool.

Following the dissolution of the monasteries in the mid-16th century, Henry VIII sold the abbey to Sir William Sharington for £783. He demolished the abbey church, using the stone to extend the building, and converted the abbey into a house, starting work in about 1539. So as not to be disturbed by villagers passing close to his residence, he is said to have sold the church bells and used the proceeds to erect a bridge over the River Ray for their convenience. Few other alterations were made to the monastic buildings themselves: the cloisters, for example, still stand below the living accommodation. About 1550, Sir William added an octagonal tower containing two small chambers, one above the other; the lower one was reached through the main rooms, and was for storing and viewing his treasures; the upper one, for banqueting, was only accessible by walking across the leads of the roof. In each chamber is a central octagonal stone table, carved with up-to-date Renaissance ornament. A mid-16th century stone conduit house stands over the spring from which water was conducted to the house. Further additions were made over the centuries, and the house now has various grand reception rooms.

In the 16th and early 17th centuries, Nicholas Cooper has pointed out, bedchambers were often named for individuals who customarily inhabited them when staying at a house. At Lacock, as elsewhere, they were named for individuals "whose recognition in this way advertised the family's affinities": the best chamber was "the duke's chamber", probably signifying John Dudley, 1st Duke of Northumberland, whom Sharington had served, while "Lady Thynne's chamber", identified it with the wife of Sir John Thynne of Longleat, and "Mr Mildmay's chamber" was reserved for Sharington's son-in-law Anthony Mildmay of Apethorpe in Northamptonshire.