The First Nigerian Republic, led by Abubakar Tafawa Balewa is overthrown in a military coup d'état.

The First Republic was the republican government of Nigeria between 1963 and 1966 governed by the first republican constitution. The country's government was based on a federal form of the Westminster system. The period between 1 October 1960, when the country gained its independence and 15 January 1966, when the first military coup d’état took place, is also generally referred to as the First Republic. The first Republic of Nigeria was ruled by different leaders representing their regions as premiers in a federation during this period.

Sir Abubakar Tafawa Balewa was the first and only Prime Minister of Nigeria. A dominant figure of Nigerian Independence, he was a conservative Anglophile. His political career spanned almost a quarter of a century.

On 15 January 1966, rebellious soldiers led by Kaduna Nzeogwu and 4 others carried out a military putsch, killing 22 people, including the prime minister of Nigeria, many senior politicians, senior Army officers and their wives, and sentinels on protective duty. The coup plotters attacked the cities of Kaduna, Ibadan, and Lagos while also blockading the Niger and Benue River within a two-day timespan, before being overcome by loyalist forces.