Harry, 32, was seen in a photograph tweeted by the British Red Cross speaking with volunteers sorting clothes for victims of the June 14 fire that killed at least 80 people.
Harry met with the volunteers for 50 minutes, according to Kensington Palace.
"Prince Harry wanted to visit the volunteers who have given many hours of their time to help sort through the huge number of donations made to the victims of the Grenfell Tower fire," said a Kensington Palace spokeswoman. "His Royal Highness was moved to hear how generous the public and businesses have been in donating all kinds of items to those affected; he thanked the teams from the British Red Cross and the Royal Mail who have worked tirelessly to sort through the donations.”
They also met with victims at a makeshift shelter set up in the immediate aftermath of the disaster. At one point William, 35, embraced an emotional woman who was desperate to find her missing husband.
This morning, Harry doled out his trademark hugs, took part in a game of handball and handed out lunches to kids in Newham East London.
The children Harry met are taking part in Fit and Fed, a new program that supports 12,000 youth at risk for hunger and isolation during school holidays.
Earlier this week, William and Harry opened up for the first time about the last days of their mother's life in a documentary for ITV.
They also talked about their regrets at not having more time with her, and how they continue to keep her memory alive.
"There's not many days that go by that I don't think of her, you know -- sometimes sad, sometimes very positively," William said. "You know, I have a smile every now and again when someone says something and I think that's exactly what she would have said, or she would have enjoyed that comment."
He continued, "My mother lives with me every day."