Sian Grigg, from Cardiff, has been nominated for an Academy Award for her work with DiCaprio on The Revenant.
He thanked Ms Grigg during his acceptance speech at the Golden Globes, where he won the best actor award for the film.
"My make-up artist, Sian Grigg, you are an unbelievable talent," he said.
Ms Grigg has worked with DiCaprio on several films including Titanic, Inception and The Great Gatsby.
"I had a lovely art teacher at Ysgol Gyfun Gymraeg Glantaf, Mr Anthony Evans," she told BBC Wales' Cymru Fyw  last week.
"He encouraged me and helped me get a place on the foundation course at Cardiff Art College."
She then specialised in make-up at London Fashion College before forging a career working on films including Saving Private Ryan, 28 Days Later, Ex-Machina and Suffragette.
But the make-up artist was keen to return to her home town, moving back to Cardiff six years ago.
"I noticed that I was always away on location so there was not much point staying in London.
"Although I've worked in many amazing countries, Wales will always be home. It's hard to beat Wales," she said.
Pembrokeshire-born actor Christian Bale has also been nominated for an Oscar in the best supporting actor category for his role The Big Short.
A Welsh make-up artist described as a "genius" by actor Leonardo DiCaprio has been nominated for an Oscar.