At least 373 people have been killed and more than 1,400 are injured, according to the Associated Press.
In a message to the president of Indonesia and the Indonesian people, the Queen said: “Prince Philip and I were deeply saddened to learn of the loss of life following the devastating tsunami in Indonesia.
“We send our sincere condolences to all who have lost loved ones and those whose homes and livelihoods have been affected.
“I pay tribute to the courage and dedication of the emergency services and the volunteers that are providing support. Elizabeth R.”
The FCO has updated travel advice, saying people in the area should follow the advice of local authorities.
It advises that before travelling to the coastal areas of western Java and the south of Sumatra, people should also check with their travel operator and monitor local media.
The tsunami comes less than three months after a 7.4-magnitude earthquake struck central Sulawesi, causing widespread damage and killing 2,256 people.
More than 70,000 homes were said to have been damaged, while communications, water and electricity infrastructure was also severely impaired.