The siege of Arrah (27 July – 3 August 1857) took place during the Indian Mutiny (also known as the Indian Rebellion of 1857). It was the eight-day defence of a fortified outbuilding, occupied by a combination of 18 civilians and 50 members of the Bengal Military Police Battalion, against 2,500–3,000 mutinying Bengal Native Infantry sepoys from three regiments and an estimated 8,000 men from irregular forces commanded by Kunwar Singh, the local zamindar or chieftain who controlled the Jagdishpur estate.

An attempt to break the siege failed, with around 290 casualties out of around 415 men in the relief party. Shortly afterwards, a second relief effort consisting of 225 men and three artillery guns—carried out despite specific orders that it should not take place—dispersed the forces surrounding the building, suffering two casualties, and the besieged party escaped. Only one member of the besieged group was injured.