Elizabeth Balgobin, former chief executive of the London Voluntary Service Council, has been appointed interim chief executive of Charities Evaluation Services.
Balgobin, who has been working in short-term positions in the voluntary sector since leaving the LVSC at the end of 2008, will take the role until July, when a permanent appointment is expected to be in place.
She replaces Colin Nee, who leaves CES at the end of December to become head of the Ireland Fund of Great Britain in January.
Rosalind Oakley, vice chair of CES, has taken over as chair from David Croisdale-Appleby, who has left after 18 months in the role.
Balgobin said: "This is a wonderful opportunity to take forward the new strategy at CES, which emphasises demonstrating effectiveness and learning from success in ways that help third sector organisations and funders alike."