In his speech, Willian said, "We have put the most powerful information technology in human history into the hands of our children - yet we do not yet understand its impact on adults, let alone the very young". "We need guidance and support to help us through some serious challenges".
William is due attend a short private meeting related to the Royal Foundation Cyber Bullying Taskforce before giving his speech.
He said: "Manchester has had a tough year, and I personally stand in awe of the way that the people of Manchester have united in bravery and support of one another".
He responded: "I'm not ginger".
As for Kate Middleton, she opted to wear Queen Mary's Lover's Knot tiara, a headpiece she has on long-term loan.
The organisation aims to make children "smarter, stronger and kinder".
He added: 'He was a sheep'.
During a visit to Media City in Salford earlier today with Kate Middleton, who is expecting their third child in April, William shared the story of George's newfound career in acting.
The couple met BBC director general Tony Hall, chief adviser of BBC Sport Neil Land and the director of BBC Children's Alice Webb as they arrived at the offices.
School pupil and Newsround contributor Josh talks about his experiences with mental health challenges at the Stepping Out session.