Hilary Duff has thanked three strangers who returned her phone after she left it on the top of her car.

The 29-year-old actress filmed an interview for The Ellen DeGeneres Show, due to air on Monday (10Oct16), and told the chat show host about a traumatic incident involving the loss of her precious cell phone.

After leaving the device on the top of her car, Hilary forgot it was there and drove off - leaving the phone to clatter into the middle of Wilshire Boulevard in Los Angeles.

"I left the gym today and left my cell phone on the hood of my car, drove about three blocks, turned onto Wilshire and it flung off," Hilary recalled. "Someone watched the whole thing happen, watched a few cars run over it, ran out in to the street and retrieved it for me."

Clearly thrilled with the fact they had Hilary's phone, the trio decided to snap a selfie with the camera before returning it to its rightful owner.

Sharing the selfie on Ellen, Hilary explained she was desperate to track the people down, explaining: "I’d want to say thank you! What would you do without your phone? I spent an hour without it and was losing my mind."

The Younger star added of the trio's bravery in grabbing the phone from one of Los Angeles' busiest roads: "I appreciate their dedication to jumping in the middle of Wilshire!"

Ellen then asked Hilary if she was worried about anything on the phone being leaked, to which the actress was deliberately coy with her answer. Pressed by the host if she had any naked snapshots on the device, Hilary laughed: "I have learned my lesson with that one, not from personal experience I have to add!"

But there was one picture on her cell of her four-year-old son Luca that Hilary is pleased wasn't made public.

"Every time we are about to take a bath, regardless of whether he has just been to the bathroom or not, the bath water starts running and he has to pee. So I have a picture of that on my phone - that’s kind of good," she giggled, before adding she "feels bad" for her son that the story is now out there.