...Heath Ledger (sniffle) and Naomi Watts were a thing?
Aussie movie stars really have been ubiquitous for a long time. Though there were important actors before our contemporary time that hailed from the land down under (Erroll Flynn, Judith Anderson, Coral Browne to name a few), the Australian takeover really began in the mid-80s when, in the space of just a few years (1983-1986), Mel Gibson ascended, Bryan Brown had a mega TV hit, Judy Davis snagged a surprise Oscar nomination and Paul Hogan wrote and starred in his own blockbuster. Australian actors have only become more ubiquitous since with more of them coming to prominence each decade.
*Oscar nominated (or winner)
1980s: Mel Gibson*, Paul Hogan*, Judy Davis*, Bryan Brown
1990s: Nicole Kidman*, Toni Collette*, Russell Crowe*, Rachel Griffiths*, Geoffrey Rush*, Hugo Weaving, Guy Pearce, Anthony LaPaglia
2000s: Cate Blanchett*, Hugh Jackman*, Naomi Watts*, Heath Ledger*, Eric Bana, Abbie Cornish, Ryan Kwanten, Isla Fisher, Simon Baker
2010s: Jacki Weaver*, Margot Robbie, Jai Courtney, Rose Byrne, Jason Clarke, Chris Hemsworth, Joel Edgerton, Sam Worthington, Ben Mendelsohn, Mia Wasikowska, Liam Hemsworth. If you include New Zealanders in the mix (Lynskey, Neill, Paquin, Lawless, Urban) it's even more crowded!