Beale, 31, had already announced a two-year contract with the star-studded, Paris-based side, but he had been expected to complete this season with the Waratahs.
“Following the COVID-19 shutdown it’s been agreed that he take up that opportunity with immediate effect,” New South Wales rugby said in a statement.
Beale played a record-equalling 148 times for the Waratahs, and has scored 156 points in 92 Tests for Australia.
“It’s a bittersweet moment to be leaving a place you’ve called home for such a long time, but this is an exciting opportunity to play overseas and the time is right to begin the next chapter in my career,” he said.
“I’m thankful for the many great people I’ve met over the journey and will cherish the memories I’ve made over the last 11 seasons.”
Australia’s director of rugby, Scott Johnson said Beale was “eager to get a head start with his new club. Under the current circumstances we viewed that as a reasonable request and he leaves with our full support”.
Beale has expressed a desire to play for Australia at the next Rugby World Cup and be involved in new coach David Rennie’s plans.
He remains eligible to play for his country because of the number of caps he has earned.