The three parties will together form the next council administration, which will rule the county over the next four years.
A statement from the three parties said the the partnership will be ‘dedicated to delivering the policy objectives and priorities shared’ by all of them.
The new ruling coalition will be called The Oxfordshire Fair Deal Alliance.
The news comes after more than a week in which negotiations have taken place to form the next council administration, after the May 6 elections left Oxfordshire County Council with no overall control.
In a joint statement, the three party group leaders, Liz Leffman (Lib Dems), Liz Brighouse (Labour) and Cllr Pete Sudbury (Green), said “We are pleased to have reached agreement to work together at this crucial and challenging moment for our county and the region.
“We have put party differences aside to developed a shared vision that is underpinned by the principles shared across our manifestos, with climate change and the environment at their heart. We look forward to delivering real and lasting change for the people of Oxfordshire.”
Further details on how the group will work will follow in the coming days.
Oxfordshire County Council’s first full meeting will be held today (May 18), in which the leader of the council and their cabinet of senior councillors will be nominated.