Moore joins from Halfords where she was group people director with responsibility for 11,000 colleagues.
She will take the lead on developing the Co-op’s “people function”, bringing enhancements to development, rewards and career opportunities.
Her remit will extend to the Co-op’s string of travel agency businesses, as well as a homeworking division.
Phil Ponsonby, Midcounties’ group chief executive, said: “Clare is an exceptional leader and joins our executive team at an important time for the society.
“Our Connected Future strategy will maximise our co-operative difference by unlocking the talents of our people for the benefit of our customers, members and communities.
“Clare has a proven track-record of working with similar multi-channel organisations to deliver programmes that have led to impressive business results.”
Moore added: “Midcounties has unique values that are rooted in its member-ownership model. At the heart of these values is democracy – listening to the views of colleagues and members to shape every major decision the society takes.
"It’s exciting to join a people-first organisation that’s keen to put colleagues at the centre of its strategy.”
She will take up her role with the Co-op later this year.