Medborgare svär trohetsed till nya kungen av Kanada

The Canadian Oath of Allegiance is a promise or declaration of fealty to the Canadian monarch, as personification of the Canadian state, taken, along with other specific oaths of office, by new occupants of various federal and provincial government offices, members of federal, provincial, and municipal police forces, members of the Canadian Armed Forces, and, in some provinces, all lawyers upon admission to the bar. The Oath of Allegiance also makes up the first portion of the Oath of Citizenship, the taking of which is a requirement of obtaining Canadian nationality. The vow's roots lie in the oath taken in the United Kingdom, the modern form of which was implemented in 1689 by King William II and III and Queen Mary II and was used in Canada prior to Confederation. The Canadian oath was established at that time in the British North America Act, 1867 (now Constitution Act, 1867), meaning that alteration or elimination of the oath for parliamentarians requires a constitutional amendment. The Oath of Allegiance has also been slightly altered and made or removed as a requirement for admission to other offices or positions through Act of Parliament or letters patent, to which proposals have been put forward for further abolishment or modification.

Samväldesrike (engelska Commonwealth realm) är var och en av de för närvarande femton olika självständiga stater vilka erkänner den person som är den brittiska monarken som sin egen statschef. Det innebär att kung Charles III innehar samtliga dessa befattningar då han är monark för varje enskilt samväldesrike; exempelvis har han i Nya Zeeland titeln som just "Kung av Nya Zeeland", men representeras lokalt av Nya Zeelands generalguvernör. Samtliga samväldesriken är även medlemmar av Samväldet av nationer (engelska Commonwealth of Nations), en sammanslutning bestående av 53 självständiga stater, varav de flesta var en gång delar av det brittiska imperiet.