Guy Pearce has celebrated his mother as a "sharp, fierce and witty" woman before her Alzheimer's diagnosis as he announced her death.
The British-born actor, best known for his role in 2000 psychological film Memento, first came to public attention when he appeared in Neighbours.
The 55-year-old reflected how he will "miss" his mother, Anne, in a post on X, formerly known as Twitter.
"Lost my beautiful Mum today. 'Kicked the bucket' as she would say," he said.
"What a sharp, fierce and witty woman Anne was, until Alzheimer's struck in 2010.
"It's been a long and winding road. A fitting song 4 ur departure Mum.
"Tracy and I will miss u enormously. We'll always love u XX."
Pearce, who has starred in Hollywood films including LA Confidential, The Hurt Locker and The Time Machine, also shared images of his mother throughout her life, including on his parents' wedding day.
He received messages of condolences from fans who said they were "sorry" for his loss.
Pearce grew up in Australia with his eldest sister Tracy, who he has previously described as having an intellectual disability.
His father, Stuart Pearce, who had served in the Royal New Zealand Air Force, died in an aircraft accident when the actor was a child.