Sarah Jones joins in June from her role as deputy director of comms at the NHS Confederation.
The new Olympic body has been set up to scrutinise spending and co-ordinate the work of various government departments, including the Department for Children, Schools and Families and the Department of Health, in the run-up to the games.
Jones, a former campaigns manager for Shelter, will also work with Locog and the Olympic Delivery Authority.
She will report into GOE director general Jeremy Beeton and Department for Culture, Media and Sport comms director Paddy Feeny.