The Daily Mail & General Trust has hired Morgan for the role after Sinclair's decision to retire in a year's time. Sinclair has been the chief executive of DMGT for 21 years.
Morgan will relocate next year to London from the US, where he is currently the managing director of DMGT's information division, but he has no direct experience of the newspaper industry, having joined DMGT in 1989 from Reed International.
Lord Rothermere, the chairman of DMGT, said: "His broad knowledge of business media, as well as his experience of consumer media, will serve him well."
The appointment coincided with a healthy set of annual results from the publisher, which reported an increase in pre-tax profits of 11 per cent to £288 million.
Ad revenues at the Associated Newspapers division rose by 8 per cent, with print revenue growing by 3 per cent to £447 million.