The Olive Tree was a denomination used for several successive centre-left political and electoral alliances of Italian political parties from 1995 to 2007.

The centre-left coalition is a political alliance of political parties in Italy active under several forms and names since 1995, when The Olive Tree was formed under the leadership of Romano Prodi. The centre-left coalition has ruled the country for more than fifteen years between 1996 and 2022; to do so, it had mostly to rely on a big tent that went from the more radical left-wing, which had more weight between 1996 and 2008, to the political centre, which had more weight during the 2010s, and its main parties were also part of grand coalitions and national unity governments.