The Right Honourable Harold Jonathan Esmond Vere Harmsworth, 4th Viscount Rothermere (born December 3, 1967) succeeded as the 4th Viscount Rothermere in 1998. He had previously been known as The Honourable Jonathan Harmsworth.
He held various positions in Associated Newspapers and was Managing Director of the Evening Standard when the sudden death of his father Vere Harold Esmond Harmsworth, 3rd Viscount Rothermere resulted in his becoming Chairman of Associated and of its parent Daily Mail and General Trust plc shortly before his 31st birthday. One notable change he has instituted is requiring directors to retire at age 75. He ranked 47th in the Sunday Times Rich List 2005 with an estimated wealth of £850m.