Taking to Instagram, the 54-year-old Canadian husband of Elton John shared a sweet snap of himself in the Chelsea Old Town Hall with sons Zachary, six, and Elijah, four, as he said he felt 'very blessed'.
The trio were pictured from behind as they gazed at a picture of the Queen.
The Toronto native captioned the shot: 'A very emotional morning for me. This morning, I was sworn in as a British citizen.
'As an immigrant, I moved to the UK more than 27 years years ago. I was welcomed with open arms. This spirit of acceptance, tolerance and diversity has allowed me to achieve a life beyond my wildest dreams. I am a very blessed man, and I am extremely proud to now carry both British and Canadian passports. @eltonjohn #ShareTheLove.'