England team spokeswoman Catherine Stewart confirmed William called and wished the players and coaches good luck during a team meeting earlier in the day. The sixth-ranked Lionesses have created a buzz back home after reaching the semifinal for the first time in four tournament appearances.
They are also only England's third team — men or women — to reach the semifinal stage of the World Cup, joining the 1966 and 1990 men's squads.
William, the Duke of Cambridge, also doubles as the nation's Football Association president.
BBC-TV reported William called the players "a true inspiration," and urged them to "go get 'em."