Up Helly Aa (/ˈʌpˌhɛliə/ UP-hel-ee-ə; literally "Up Holy [Day] All") refers to any of a variety of fire festivals held annually in the Shetland Islands of Scotland, in the middle of winter to mark the end of the yule season. The festival involves a procession of up to a thousand guizers in Lerwick and considerably lower numbers in the more rural festivals, formed into squads who march through the town or village in a variety of themed costumes.
The current Lerwick celebration grew out of the older yule tradition of tar barrelling which took place at Christmas and New Year as well as Up Helly Aa. Squads of young men would drag barrels of burning tar through town on sledges, making mischief. Concerns over public safety and levels of drunkenness led to a change in the celebrations, and saw them drawing inspiration from the islands' Viking history. After the abolition of tar barrelling around 1874–1880, permission was eventually obtained for torch processions. The first yule torch procession took place in 1876. The first torch celebration on Up Helly Aa day took place in 1881. The following year the torchlit procession was significantly enhanced and institutionalised through a request by a Lerwick civic body to hold another Up Helly Aa torch procession for the visit of Alfred, Duke of Edinburgh. The first galley was introduced and burned in 1889. The honorary role of the 'Jarl' was introduced to the festival in the early twentieth century.