A combined audience of 11.5 million people watched Harry and Meghan tie the knot on 19 May 19 – 8.9 million on BBC One and 2.6 million on ITV.
But 17.6 million tuned in for the wedding of the Duke and Duchess of Cambridge in April 2011. A total of 13.6 million on BBC One plus 4 million on ITV watched William marry Kate Middleton.
The figures mean the combined audience for Harry’s wedding was 35 per cent down on the equivalent figure for his brother.
Harry also failed to pull in as many viewers as his uncle Prince Edward, whose wedding in June 1999 to Sophie, Countess of Wessex, enjoyed a combined BBC One/ITV audience of 14.8 million.
The new figures published by Barb are consolidated ratings and include those who recorded the wedding and watched it up to seven days later.
Royal weddings have a history of being one of the most-viewed TV events of the year, but 2018 may turn out to be different.
Harry and Meghan’s ratings of 11.5 million could be beaten next month by audiences for England’s matches in the World Cup.
And in the autumn, ratings of more than 12 million are likely for the BBC’s Strictly Come Dancing and ITV’s I’m A Celebrity ... Get Me Out Of Here!.
The biggest ever UK TV audience for a royal wedding was recorded in July 1981 when an estimated 28 million watched Charles marry Lady Diana Spencer.