David Letterman on Jay Leno: 'He's the most insecure person I've met'

David Letterman has described late-night rival Jay Leno as "the most insecure person" he has ever known.

Leno was a frequent guest on Letterman's NBC series in the 1980s, but the relationship soured once Johnny Carson left The Tonight Show in the early 1990s.

David Letterman presenting the 'Late Show'

PA Images / John Paul Filo/Landov

Jay Leno filming a segment for 'The Tonight Show with Jay Leno' on Melrose Avenue

Both presenters were in the running to replace Carson, with Leno eventually scoring the job and allegedly upsetting Letterman in the process.

Letterman spoke about his long rivalry with Leno on Oprah's Next Chapter and explained his mixed feelings about his former friend.

"I will say, and I'm happy to say, that I think he is the funniest guy I've ever known," he insisted to Oprah Winfrey. "Just flat out, if you go see him do his nightclub act, just the funniest, the smartest, a wonderful observationist and very appealing as a comic."

The Late Show host added: "The fact that he is also maybe the most insecure person I have ever known - I could never reconcile that."

David Letterman

Tensions between Leno and Letterman appear to have thawed in recent years, with the pair appeari! ng with Oprah Winfrey in a Super Bowl commercial for The Late Show in 2010.

That Super Bowl advert was also originally supposed to include Conan O'Brien, who also has expressed ill-will towards Leno due to being replaced by the presenter on The Tonight Show three years ago. O'Brien ultimately declined to appear in the commercial.

Oprah's Next Chapter airs its Letterman interview on Sunday, January 6 at 9/8c on OWN.

Watch a preview of the interview below:

First Look: Oprah's Next Chapter with David Letterman