In a statement, the museum said that Watson had gone "beyond the point of acceptable debate," The Telegraph reported. The talk, scheduled for Friday, was sold out.
Watson was a post-doctoral student when he and Francis Crick, working at the Cavendish Laboratory at Cambridge University, decoded the structure of the DNA molecule. The two men shared the 1961 Nobel Prize for medicine with Maurice Wilkins of Kings College.
Before his arrival in London to promote his latest book, Watson gave an interview to The Sunday Times in which he suggested that racial differences in achievement are a result of inherited differences in intelligence.
Watson's schedule includes five talks, including engagements at Oxford and Cambridge, and a reception in his honor by the Royal Society.
Now 79, Watson is head of the Cold Spring Harbor Laboratory in New York State.