Latham joins next week as the DCMS learns the fate of the London 2012 Olympic bid.
She effectively replaces Bill Bush, who left to become PR chief for the FA Premier League (PRWeek, 13 May).Latham will be Jowell's principal aide on comms and will provide policy advice in her additional role as Minister for Women.
Latham, a US national, joined Freuds over two years ago, with clients including AOL Time Warner and VisitLondon. She was previously MD of Philip Gould Associates and ran President Clinton's scheduling office at the White House. Freuds said it did not plan to replace her.