The 23-year-old Barty ended a 46-year wait for an Australian champion in the women's singles at the French Open on Saturday but took time out in Paris to wish her compatriots success against Italy in Valenciennes on Sunday.
"A shout here to the Matildas and our World Cup campaign that's starting here in France soon," she said in a video clip posted on social media by the WTA Tour.
"Sammy Kerr's our new captain, leading the way, good luck girls."
Kerr, Australia's highest-profile footballer and one of the best strikers in the world, had clearly been paying close attention to Barty's progress at Roland Garros while preparing for the World Cup.
"YES YOU DID! Congrats @ashbar96," she posted on Twitter after the final on Saturday.
The Matildas, who also play Brazil and Jamaica in the opening round group stage, have never gone further than the quarter-finals at the World Cup and are 14-1 chances to lift the trophy in Lyon on July 7.
They can perhaps take comfort from the fact that Barty was a 20-1 shot to win the French Open at the start of her fortnight in the French capital.
(Writing by Nick Mulvenney in Sydney, editing by Amlan Chakraborty)
