Saturday's royal wedding is officially the most watched television event of the year in the U.K. BBC One led the way with an average audience of 8.7 million viewers, hitting a peak of 13.1 million. Over on ITV, the average was 2.5 million, hitting a peak of 3.6. In total, just below 18 million watched Prince Harry and Meghan Markle tie the knot on TV..