"She was great at defying expectation," he added. "She managed to grow very old and somehow, not old enough. We'll miss you, Betty. Now you know the secret."
He also shared a photo of White giving the thumbs up on a poster for his first Deadpool movie.
Reynolds and White were longtime friends and once starred together in the 2009 film The Proposal. She played his grandmother in the movie but they've had a running joke ever since that she was his ex-girlfriend, and they've frequently teased each other through the media over the years.
Reynolds has also been first in line each year to wish her happy birthday, and they spoke about their friendship in a recent People profile that was meant to celebrate her 100th birthday.
"I've heard Ryan can't get over his thing for me," White said in the profile. "But Robert Redford is The One."
Reynolds described her in the interview as a "typical Capricorn. Sleeps all day. Out all night boozing and snacking on men."
White would've turned 100 on January 17 but died just a few weeks shy of that milestone.
Many actors and others joined Reynolds in remembering the beloved Golden Girls star, who remained a sharp comedian right up until the day she died.
She showcased that wit in her interview with People, particularly when they asked her the classic "What's your secret to living a long life?" question.
White joked that she tries to “avoid anything green” in her diet.
“I think it’s working,” she said.
Her spokesperson confirmed her death to People on Friday but did not share the cause.
