The siege of Fort William took place in the Scottish Highlands during the 1745 Jacobite Rising, from 20 March to 3 April 1746.
On 1 February 1746, the Jacobites abandoned the siege of Stirling Castle and withdrew to Inverness to wait for spring. This period was used to reduce government strongpoints in the Highlands, including Blair Castle and Fort Augustus; after its surrender on 1 March, they moved onto Fort William.
Advance elements of the Jacobite force arrived outside the fort on 8 March; operations began on 20 March but made little progress. When the Duke of Cumberland and his army left Aberdeen in early April, the besiegers were recalled to Inverness and the siege abandoned.