Commonwealth presidents and prime ministers have decided Charles will succeed the Queen and lead the global institution that has a combined population of 2.4 billion.
The Queen made a personal appeal to world leaders on Thursday to choose her son for the role.
During the opening of the Commonwealth Heads of Government Meeting she told them it was her "sincere wish" that the family of nations would one day decide the prince should carry on the Commonwealth work started by her father King George VI.
Tom Topping: Heartbroken daughter says ‘world is totally shattered’ after father’s shock death - funeral details released
Linfield v Portadown Sunday clash: Breakers of the Sabbath will answer to God
Michelle O’Neill has kicked sand in the face of victims of terrorism
College lecturer dies while on holiday
‘Warped revisionism’ claim after Sinn Fein praise for hunger striker
The leaders came to their decision during discussions held at their retreat, at Windsor Castle, where informal talks are held without aides or advisers present.
Lloyd Dorfman, chairman of the Prince's Trust and Prince's Trust International, welcomed the news that Charles is to become the next head of the Commonwealth.
He said: "At present, seven of the nine countries where we run programmes are in the Commonwealth including Australia, Barbados, Canada and India, so we are already supporting thousands of young people in Commonwealth countries.
"I have seen the prince operating with his charities at close quarters. His vision and efforts are making a big difference and changing lives.
"As head of the Commonwealth, the prince will be able to amplify this work and bring to the table his extensive experience, wisdom and passion."