She paid tribute to the emergency services battling to control the blazes, and praised the “true Australian spirit” as other States and Territories offered their support.
Large swathes of north-east Australia have endured unprecedented fire danger with 138 wildfires across Queensland state last week, forcing schools to be closed and thousands of homes to be evacuated.
The fire danger was rated catastrophic in areas of central Queensland, the first time the highest rating had been applied to the state.
The Queen said: “Prince Philip and I are saddened to hear of the unprecedented fires impacting so many people in Queensland.
“I pay tribute to the commitment and dedication of the firefighters, other emergency services personnel, and the volunteers who are working tirelessly to contain the fires.
“In true Australian spirit, it is heartening to know other States and Territories are working alongside Queensland in support of the relief effort.
“Our thoughts and prayers are with you all at this difficult time.”