The Royal William Victualling Yard in Stonehouse, a suburb of Plymouth, England, was the major victualling depot of the Royal Navy and an important adjunct of Devonport Dockyard. It was designed by the architect Sir John Rennie and was named after King William IV. It was built between 1826 and 1835 and occupies a site of approximately 16 acres (65,000 m²) being half of Western Kings, north of Devil's Point.

The Yard was released from the Ministry of Defence (MOD) in 1992 and subsequently passed to the Plymouth Development Corporation. Upon the Corporation's closure in 1999, the Yard was then passed to The South West Regional Development Agency (SWRDA) who funded and carried out the extensive c. £60m restoration of the structural fabric of the majority of principal buildings and infrastructure within the yard between 1999 and 2008. During this period the buildings were recategorised from Scheduled Monuments to Grade I/II listed buildings. Private sector development partners Urban Splash were then engaged to carry out the specialist conversion of the site into a mixed-use development.

Described as the grandest of the royal victualling yards, 'in its externally largely unaltered state it remains today one of the most magnificent industrial monuments in the country'.

Plymouth had been involved in victualling the English fleet since the 13th century. In the 1650s the Commonwealth government built victualling storehouses on Lambhay Hill next to Hoe Fort (which would soon be rebuilt as the Royal Citadel), with manufacturing taking place at various locations around the old harbour and a wharf providing a loading area for ships in Sutton Pool (albeit only accessible at high tide).

Following the establishment of a Royal Navy Dockyard in what would later be known as Devonport, in 1690, these victualling premises expanded substantially. A new Victualling Office was opened in Lambhay in 1707, overseen by an Agent Victualler. From 1729, brewing took place across the Hamoaze at Southdown, where a cooperage was also established; it was capable of producing up to 80 tuns of beer per week and had its own wharf (again, only accessible at high-tide). In 1745, the Lambhay site was further expanded, with the construction of two bakehouses, a slaughterhouse and several storehouses, as well as a new wharf. (The slaughterhouse was later removed to Devil's Point.) The bakeries were capable of producing 50 tons of bread each week, however, the mills which produced the flour were three-quarters of a mile away, making baking a difficult process; nevertheless, these facilities continued in use until 1831. These mills were leased by the Victualling Commissioners from the Town Corporation. The Victualling Office depended on local farmers for fresh produce to supplement the dry goods it provided; inevitably, the local economy could be significantly affected by the varying needs of the fleet.

Towards the end of the Napoleonic Wars, the Victualling establishment at Lambhay is described as 'an extensive range of buildings lying by the side of the Catwater harbour', including:

The wharf in front had a small jetty attached.

Following the establishment of the Royal William Victualling Yard, the old Yard at Lambhay was closed; its buildings were sold in 1835 and from 1847 several of them were used as a Government Emigration Depot. In 1897 they were renamed Elphinstone Barracks, accommodating a torpedo depot of the Royal Engineers, before being demolished in the 1930s.