“I also pay tribute to the bravery and sacrifice of the officers from the Royal Canadian Mounted Police and other police services who selflessly responded to these devastating attacks, and to the emergency services who are supporting those who have been injured and affected.
“My thoughts and prayers are with the people of Nova Scotia and all Canadians at this tragic time,” she concluded.
Her Majesty also shared the message in French, the second most common language in the Commonwealth country.
The Queen’s heartfelt message comes as she celebrates her 94th birthday away from family in isolation, due to the coronavirus pandemic.
Prince William and Kate Middleton led the birthday tributes by taking to Instagram and sharing a sweet image of themselves with the Queen at the Royal Chelsea Show last May.
"Wishing Her Majesty, The Queen a very happy 94th Birthday today!" the royal couple captioned the snap, along with cake and balloon emojis.
The delightful photo shows the trio as they look at the floral gardens featured at the annual event, which included a garden project co-designed by the Duchess of Cambridge herself.
Kate's "Back to Nature" garden was created to highlight the significance of spending time outdoors, which can promote many positive mental and physical benefits.