Heir to the throne William celebrated England’s “phenomenal performance” as he tweeted a personal message of congratulations after the 3-1 semi-final victory over Australia.
The King also sent his “warmest congratulations” from all the royal family, hailing the “mighty Lionesses” as an “inspiration on and off the pitch”.
It is the first time the Lionesses have reached the final of a World Cup, and the first time an England football team has competed in a World Cup final since the men’s side beat West Germany in 1966.
William, who is president of the Football Association (FA), will not be in Australia to witness the clash against Spain on Sunday, Kensington Palace confirmed.
Instead, he will watch the match on television as he cheers the Lionesses on.
In October, he was not planning to attend the men’s World Cup, staged by controversial hosts Qatar, due to a busy winter schedule.
But it was understood his office might have looked at making arrangements if Gareth Southgate’s team had reached the final.
In the end, the team lost 2-1 to France in the quarter-finals.
It is understood William made the decision not to travel to the Lionesses’ final because a trip to Australia would involve flying across the world for a very short period of time, and there were other ways he could show support for the team.
The prince has made tackling climate change one of his priorities, launching the Earthshot Prize to find solutions to repair and regenerate the earth.
His brother the Duke of Sussex has often been criticised for his flying habits in the past, in particular his previous use of private planes.
The King, who is also King of Australia, wrote: “My wife and I join all our family in sending the mighty Lionesses our warmest congratulations on reaching the final of the World Cup, and in sharing our very best wishes for Sunday’s match.
“While your victory may have cost the magnificent Matildas their chance for the greatest prize in the game, both teams have been an inspiration on and off the pitch – and, for that, both nations are united in pride, admiration and respect.”
The King, who is on his annual holiday in Scotland, signed his message to manager Sarina Wiegman and her squad Charles R.
Queen Elizabeth II attended the 1966 World Cup final at Wembley and presented captain Bobby Moore with the trophy.
William, who is on his summer break, wrote: “What a phenomenal performance from the @Lionesses – on to the final!
“Commiserations to @TheMatildas, you’ve played brilliantly and been fantastic co-hosts of this World Cup. W”
As a future monarch, William will one day become king of Australia as well as the UK, unless Australia becomes a republic in the meantime.
At the Changing the Guard ceremony at Buckingham Palace on Wednesday morning, the Band of the Welsh Guards, led by female conductor Major Lauren Petritz-Watts, showed its support for both teams by playing Sweet Caroline for the England squad and Waltzing Matilda for Australia.
William saw the Lionesses win the European Championship last year, presenting them with their medals at Wembley.