The Dominion of Newfoundland was a British Dominion from 1907 (before which the territory had the status of a British colony, self-governing from 1855) to 1949. The Dominion of Newfoundland was situated in northeastern North America along the Atlantic coast and comprised the island of Newfoundland and Labrador on the continental mainland. The dominion was self-governing from 1907 to 1934 when it voluntarily gave up self-government and reverted to direct control from London — one of the few countries that has ever voluntarily given up direct self-rule. Between 1934 and 1949 a six-member Commission of Government (plus a governor) administered Newfoundland, reporting to the Dominions Office in London. Newfoundland remained a de jure Dominion until it joined Canada in 1949 to become Canada's tenth province.

The Union Jack was adopted by legislature as the official national flag of the Dominion of Newfoundland on May 15, 1931, before which time the Newfoundland Red Ensign, as civil ensign of Newfoundland, was used as the national flag (though unlegislated)