Britain's head of state sent the team his "warmest congratulations" after their 2-1 win against The Netherlands on Wednesday evening and his "very best wishes" for Sunday's final against Spain.
But he urged them to play with the nation's blood pressure in mind after fans endured the suspense of a last-gasp equaliser in the second round against Slovakia, a penalty triumph against Switzerland in the quarter-final, and Ollie Watkins' 90th-minute winner to send them through to the final.
"If I may encourage you to secure victory before the need for any last minute wonder-goals or another penalties drama, I am sure the stresses on the nation's collective heart rate and blood pressure would be greatly alleviated!" he said.
"Good luck, England."
Charles's son, William, who is president of the Football Association, singled out Aston Villa striker Ollie Watkins for praise after he came off the bench to score the winner.
"What a beauty, Ollie! Congratulations England! #EURO2024 Finalists," wrote the Prince of Wales, who supports the Birmingham club.
William is likely to travel to Berlin for the final.
Prime Minister Keir Starmer, an Arsenal fan who watched some of the game while attending a Nato summit in Washington, has confirmed he will also travel for the match.
