The Duke of Cambridge is to feature in the UK's leading gay magazine, Attitude.
William told a member of staff during a visit to the American Embassy that he will be appearing in the monthly publication, which comes out on Wednesday.
Mike Buckley, managing director of Attitude, confirmed the news and said: "We will have some exciting announcements to share soon."
The Duke and Duchess of Cambridge signed a book of condolence for victims of the gay nightclub shooting in Orlando at the embassy in Westminster, central London, on Tuesday.
Lone gunman Omar Mateen, 29, left 49 people dead and dozens of others wounded in the massacre at Pulse in the Florida city on Sunday.
After signing a message, the couple spoke to staff who have worked on LGBT issues.
Craig Petty, president of LGBT association Glifaa, said the Duke told him he would be appearing in the magazine.
"I told him what I do and he said he's going to be in Attitude magazine," he added.
"I was really nervous about meeting the royal couple but they are both great at putting you at ease.
"I think it's great that they have come here today to show their support."
A Kensington Palace spokesman said: "We look forward to speaking about this soon."
A source said: "It's all very exciting. For the Duke to have mentioned it today is really nice to know."It's been set up for months."