The Barbie star, 33, wore a t-shirt and held a placard over her head in support of the SAG-AFTRA union as she took part in the march from Netflix Studios to Paramount Studios in Los Angeles on Wednesday.
Robbie’s appearance comes just months after she finished a whirlwind promotional tour of her latest film Barbie, which became the Warner Bros. Studios’ highest-ever grossing film with box office sales of more than £1 billion globally.
It is now sitting just outside the top 20 highest-earning films of all time – and is likely to climb still further.
The union argues that actors’ wages and base pay have failed to keep up with inflation, while writers are worried they may be replaced with AI bots.
The Writers Guild of America has been on strike since early May, and was joined by the SAG-AFTRA actors’ union in July, putting production of major films and television shows to a screeching halt.
SAG-AFTRA said it is the world’s largest labour union representing performers and broadcasters.
Actors are calling for an 11 per cent pay rise among a raft of demands, while the union said the streaming business model “has eroded” actors’ “residuals income”.
The SAG-AFTRA is calling for casts to “share in the revenue generated when their performances are exhibited on streaming platforms”.
“This would allow casts to share in the success of high-performing shows,” the union said.
The strike kept most stars away from the Venice Film Festival earlier this month, and even the few A-listers who did venture into town seemed guilty about being on the red carpet rather than the picket line.
The strikes have shut down both television and movie productions in Hollywood, but some projects that have no affiliation to the big studios are receiving passes to keep on working or do normal promotions if they comply with the most recent union demands.