O'Sullivan said her title will stay the same, but will become a 'new marketing role', allowing her to focus on helping individual countries develop brand strategies.
'This will also allow us to develop our extranet, which helped co-ordinate information about the Asian tsunami,' said O'Sullivan. As the tsunami struck during a holiday, many offices were closed.
Flynn will take charge of a seven-strong web and media team – divided between the UK, US, Switzerland and Spain – on 1 May.
Oxfam International is the charity's 'international secretariat' and works as an umbrella group to support the brand globally and help individual countries keep comms campaigns on message.
The charity had a spectacular 2005 and is keen to sustain the momentum generated by the Make Poverty History campaign and its part in the tsunami relief effort.