John Sparrow David Thompson, Canadian lawyer, judge, and politician, 4th Prime Minister of Canada (died 1894)

Sir John Sparrow David Thompson was the fourth prime minister of Canada, serving from 1892 until his death in 1894. He had previously been fifth premier of Nova Scotia for a brief period in 1882, and as of 2025, is the only prime minister who was previously a provincial premier.

The prime minister of Canada is the head of government of Canada. Under the Westminster system, the prime minister governs with the confidence of a majority of the elected House of Commons; as such, the prime minister typically sits as a member of Parliament (MP) and leads the largest party or a coalition of parties. As first minister, the prime minister selects ministers to form the Cabinet.