James, 20, was a key figure in Australia's 2022 FIFA U20 Women's World Cup campaign, and arrives at Perth following 12 league appearances for Melbourne City last season.
Galic, 24, joins Annalise Rasmussen in putting pen to paper on a contract with the A-League Women expansion side, as head coach Emily Husband begins to piece together the club's inaugural playing squad.
Rule is the third Sydney FC player to join the FA Women's Super League club this off-season, following Mackenzie Hawkesby and Madison Haley in putting pen to paper on a contract at the English club.
Sam Kerr, Kyah Simon, Clare Polkinghorne, Lydia Williams and Tameka Yallop emerged and inspired the next generation when our domestic women's league was born in 2008, writes David Davutovic.
Mackenzie Hawkesby has become the latest Australian to head to the Women's Super League, with the Sydney FC playmaker joining Brighton and Hove Albion.