Prince Harry is suing Associated Newspapers, one of Britain's biggest publishers, his representative said.
It comes months after his wife, Meghan Markle, successfully won a privacy claim against the Mail on Sunday for printing extracts of a letter she wrote to her estranged father in 2018.
Harry's representative provided no details about which of the titles is being sued or why.
Associated Newspapers, publishers of the Daily Mail and Mail on Sunday, declined to comment.
Harry and Meghan, formally known as the Duke and Duchess of Sussex, moved to California two years to lead a more independent life.
Harry has previously said he stepped back from his royal duties because the "toxic" British press had been destroying his mental health.