He also said he has not spoken to his brother Harry yet since the interview, “but will do”.
The Duke of Cambridge was on a visit to an east London school when he made the comments, but did not stop to speak on it further.
The visit was the first time William and Kate Middleton have been seen in public since Harry and Meghan’s bombshell interview with Oprah Winfrey, which aired in the UK on Monday night.
The couple toured School21 in Stratford, east London, to mark the return of children to schools this week and the rollout of a mental health project launched by Kate to secondary schools.
As William left, a reporter asked: “Is the royal family a racist family, sir?”
He replied: “We’re very much not a racist family.”
The monarchy has been rocked by allegations made by Harry and Meghan during the two-hour long interview, including of racism and poor treatment of the Duchess of Sussex’s mental health while they were in the UK.