The Skeleton Army was a diffuse group from Weston-super-Mare, active particularly in Southern England, that opposed and disrupted The Salvation Army's marches against alcohol in the late 19th century and best known for an attack in Bethnal Green in London. Clashes between the two groups led to the deaths of several Salvationists and injuries to many others.

The earliest reference to an organised opposition to The Salvation Army was in August 1880 in Whitechapel, when The Unconverted Salvation Army was founded with its flag and motto of "Be just and fear not".

In 1881, Skeleton Armies were raised in Whitechapel, Exeter and Weston-super-Mare, and the name was quickly taken up elsewhere as other groups were formed in the south of England; there are no records of Skeleton Armies north of London. Membership was predominantly lower to middle working-class.

In 'Blood on the Flag', Major Nigel Bovey identifies 21 towns and cities that are north of London -- three in Scotland -- in which the Skeleton Army opposed The Salvation Army.

The "Skeletons" recognised each other by various insignia used to distinguish themselves. Skeletons used banners with skulls and crossbones; sometimes there were two coffins and a statement like, "Blood and Thunder" (mocking the Salvation Army's war cry "Blood and Fire") or the three Bs: "Beef", "Beer" and "Bacca" – again mocking the Salvation Army's three S's – "Soup", "Soap" and "Salvation". Banners also had pictures of monkeys, rats and the devil. Skeletons further published so-called "gazettes" considered libellous as well as obscene and blasphemous.

Several techniques were employed by the "Skeletons" to disrupt Salvation Army meetings and marches; these included throwing rocks and dead rats, marching while loudly playing musical instruments or shouting, and physically assaulting Salvation Army members at their meetings.

Although George Scott Railton, second in command of the Salvation Army, claimed the Skeleton Army first started in Weston-super-Mare in 1881, contemporary press reports show that it first appeared in Exeter in October 1881. In Weston-super-Mare, in March 1882 Captain William Beatty, Thomas Bowden and William Mullins were given a three-month prison sentence by the magistrates for a breach of the peace when they broke a local ban on processions.

This led to the case of Beatty v Gillbanks (1882), which held that the Salvation Army was acting lawfully when marching, despite knowing that their assembly could well lead to riots. As their intentions were ultimately peaceful and unrelated to the cause of inciting riot, the court found their actions to be within the limits of the law. That it was known that their marching may cause riots was not found to be a breach of the law, as it was the actions of antagonistic parties including the Skeleton Army which led directly to the riotous behaviour. The convictions against Beatty and the two other Salvationists were later quashed by the High Court and costs were awarded against the sentencing magistrates.