| Conflict: | Siege of Vellore |
| Partof: | Second Anglo-Mysore War |
| Date: | 1780 – 1782 (2 years) |
| Place: | Vellore, Kingdom of Mysore |
| Result: | British victory |
| Combatant1: | British East India Company |
| Commander2: | Hyder Ali |
The siege of Vellore was an intermittent series of sieges and blockades conducted during the Second Anglo-Mysore War by forces of the Kingdom of Mysore against a British East India Company garrison holding the fortress at Vellore, located in the present-day Indian state of Tamil Nadu.
First besieged in 1780, Mysore's ruler Hyder Ali eventually reduced the siege to a blockade due to the need for troops elsewhere. The blockade was ineffectively maintained until 1782 before being abandoned. The British successfully resupplied the garrison of Colonel Ross Lang four times.