US chat show host David Letterman publicly apologised to Paris Hilton on Friday night for hurting her feelings during an infamous 2007 interview.

The late-night TV presenter upset the socialite when he grilled her about her prison stint last year, and refused to change the subject when Hilton begged him to.

So, when Hilton agreed to return to Letterman's 'The Late Show' to promote her new film 'The Hottie & The Nottie', the host decided it was time to make amends.

Before introducing the hotel heiress, Letterman said: "I made a fool of myself and I hurt the woman's feelings. I went too far."

The host revealed Hilton was adamant she'd never appear on the show again, but he tracked her down to apologise, sent her a letter and flowers, and implored her to change her mind: "I said… let me apologise to you in person.

"In 26 years of being on the air, I have offended thousands of people… but Paris, God bless her, has the backbone to come and be on the show."