Lalgie, who arrived from Britain on Sunday,  said: “It is a privilege to have begun my service as Governor of Bermuda. My family and I look forward to settling into Bermudian life.”
Premier David Burt, Chief Justice Narinder Hargun and Cabinet Secretary Marc Telemaque attended the swearing-in ceremony as Bermuda grapples with a sudden surge in COVID-19 cases.
A government spokeswoman said “all necessary health guidelines and precautions were observed” at the event.
She said a public ceremony to mark the arrival of the new Governor would be held next year “when conditions become safe to do so”.
Lalgie replaces John Rankin, a Scotsman, who has left to take up a similar post in the British Virgin Islands, a sister British Overseas Territory.