In a testy interview with NBC's "Today" show aired on Monday, the 71-year-old Clinton was also asked for his thoughts on the #MeToo movement.
The former US president is on a book tour to promote his new book, "The President Is Missing," co-written with best-selling author James Patterson.
But it's his time in the Oval Office -- specifically his affair with Lewinsky -- that is drawing scrutiny.
"I apologized to everybody in the world," Clinton said when asked if he had apologized to Lewinsky for his affair with the then 22-year-old White House intern.
"I have not talked to her," Clinton said. "I have never talked to her."
"But I did say publicly on more than one occasion that I was sorry," he said. "That's very different. The apology was public."
Asked about the #MeToo movement, Clinton said "I like the #MeToo movement.
"It's way overdue," he said. "It doesn't mean I agree with everything.
"I still have some questions about some of the decisions which have been made," he said without elaborating.