The Prince, who will become a first time father any day now, was given a rock star reception as he made his way to the opening of a youth centre in Barking.
Fans were seen waving and screaming with excitement as the dad-to-be stopped and greeted as many people as he could before entering the facility to carry out his official duties.
It comes after he and heavily pregnant wife Meghan Markle revealed their plans to keep details of their newborns arrival a secret for at least a few days to allow them to celebrate as a new family.
Meanwhile, Harry's cousin-in-law Mike Tindall recently revealed just what kind of parent he thinks the 34-year-old will be.
Harry, is of course god father to Mike and wife Zara Tindall's baby girl, Lena.
"He'll be a great parent," the former rugby star told Good Morning Britain.
"He's always been good around the kids whenever they get together so looking forward to it. Hopefully it'll all go well."