The Greengage is an edible drupaceous fruit, a cultivar of the plum, Prunus domestica 'Reine Claude'. It was developed in France from a green-fruited wild plum originally found in Asia Minor. It is identified by its small, oval shape, smooth-textured flesh, and ranging in colour from green to yellow, grown in temperate areas. They are known for their rich, confectionery flavour that cause them to be considered one of the finest dessert plums.

The name 'Reine Claude' is after the Queen-consort of King Francis I of France. Greengages were imported into England from France and cultivated by Sir Thomas Gage, from whom they allegedly get their English name. As the legend goes, Gage's gardener named it after the family when labels identifying the trees brought over from France were lost in transit. Soon after, Greengages were cultivated in the American colonies, even taking a place on the plantations of George Washington and Thomas Jefferson. However, their cultivation in North America has declined significantly since the Eighteenth Century.

Greengages breed more-or-less true from seed, and several similar cultivars produced from seedlings are now available; some of these include other plum cultivars in their parentage:

• 'Bryanston' (UK)
• 'Cambridge Gage' (UK)
• 'Denniston's Superb' (USA)
• 'Golden Transparent' (UK)
• 'Laxton's Gage' (UK)
• 'Laxton's Supreme' (UK)
• 'Ontario' (Canada)
• 'Reine Claude de Bavay' (Belgium)
• 'Transparent Gage' (France)
• 'Washington' (USA)