But today we're discussing her latest children's book - My Mom Is A Foreigner, But Not To Me - inspired by her Scottish mother Anne Love Smith, a psychologist and social worker who died suddenly in 2009 after an embolism.
Moore was on a plane to see her at the time, so never got to say goodbye.
"It never goes away. It's the greatest loss of my life," said the actress.
"She was my role model, the one who told me I could do anything I wanted to do. She was only 20 years older than I was, so I had an expectation that we'd be old ladies together.
"You don't cope. People have this idea that grief is something you get over, but I don't think you ever get over that kind of a loss."
Her picture book pays homage to all mothers, celebrating the diverse world we live in.
"My mother came here [to the US] from Scotland when she was 10 years old. It's a challenging thing," she said.
"In the United States we talk so much about assimilation, that we're all multicultural and we all assimilate, but that was not my experience growing up. My experience was that my mother was very Scottish.
"She was only 20 when I was born and she hadn't changed or become 'Americanised'. When I was growing up, she'd say, 'Remember you are not American'."
The tales in the book are reflective of the experiences Moore had as a youngster, having a "foreign" mum.
"People would say, 'Why does your mom talk so funny?' I knew that she was different. She'd always braid my hair, we'd eat different kinds of food."
The actress, who's lived in New York for 30 years, is no stranger to a feeling of displacement.
She had a peripatetic childhood, born at an army base in North Carolina, the daughter of a paratrooper and later a military judge. The family moved to 23 different locations, with Moore attending nine schools.
She wasn't a confident child, she admitted. "I didn't mind my [red] hair, but I just hated my freckles. Kids would say things like, 'Are you dirty?' I didn't like not being able to go to the beach and get a tan."
It's this which inspired her successful children's book series, Freckleface Strawberry, all now New York Times bestsellers, with a message that children can overcome hurdles.
* My Mom Is A Foreigner, But Not To Me, by Julianne Moore, is published by Chronicle Books.
- PA