Paul stepped out with wife Nancy Shevell in London on Tuesday afternoon.
He easily mingled with pedestrians and tourists during a walk through Hyde Park, close to the Serpentine, in London.
Their appearances comes just days after Paul joined James Corden for the carpool Karaokes segment of his hugely popular The Late Late Show.
James, 39, giggled like an excited schoolboy as he belted out the lyrics to Drive My Car with The Beatles icon.
Casually-clad Paul put on an animated display as he sang loudly and rocked out with the funnyman in the plush vehicle.
They could be heard singing: ‘Yes, I’m gonna be a star / Baby, you can drive my car / And maybe I’ll love you.’ James and Paul were in high spirits while they sang the chart-topping band’s 1965 song for the hilarious segment.
The Peter Rabbit star confessed it was ‘mind-blowing’ to have the ‘most respected musician on the planet’ Paul join him for the segment.
He told: ‘It’s all memorable. It’s kind of insane, if you think about it — you’re talking about possibly the most famous person in the world.He’s the most respected musician on the planet, and that he would come to do a segment on our show is mind-blowing to me. He told me a story about how he wrote Let It Be, which I’d never heard before. It really moved me, so I can’t wait to share it with people.’