National Day, celebrates the withdrawal of United Kingdom from Bahrain, making Bahrain an independent emirate in 1971.

A national day is a day on which celebrations mark the statehood or nationhood of a state or its people. It may be the date of independence, of becoming a republic, of becoming a federation, or a significant date for a patron saint or a ruler.

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The UK includes the island of Great Britain, the north-eastern part of the island of Ireland, and most of the smaller islands within the British Isles, covering 94,354 square miles (244,376 km²). Northern Ireland shares a land border with the Republic of Ireland; otherwise, the UK is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. It maintains sovereignty over the British Overseas Territories, which are located across various oceans and seas globally. The UK had an estimated population of over 68.2 million people in 2023. The capital and largest city of both England and the UK is London. The cities of Edinburgh, Cardiff and Belfast are the national capitals of Scotland, Wales and Northern Ireland respectively.

Bahrain, officially the Kingdom of Bahrain, is an island country in West Asia. Situated on the Persian Gulf, it comprises a small archipelago of 50 natural islands and an additional 33 artificial islands, centered on Bahrain Island, which makes up around 83 percent of the country's landmass. Bahrain is situated between Qatar and the northeastern coast of Saudi Arabia, to which it is connected by the King Fahd Causeway. The population is 1,501,635 as of 2023, of whom 712,362 are Bahraini nationals and 789,273 are expatriates spanning 2,000 ethnicities. Bahrain spans some 760 square kilometres (290 sq mi) and is the third-smallest nation in Asia after the Maldives and Singapore. The capital and largest city is Manama.