Glera is a white grape variety of Italian origin, which until 2009 was typically referred to as Prosecco. Glera is a rather neutral grape variety which is mainly grown for use in sparkling Italian wine styles, frizzante or spumante, from the various Prosecco DOC and DOCG areas, plus still wines also exist. It is grown mainly in the Veneto region of north Italy, traditionally in an area near Conegliano and Valdobbiadene, in the hills north of Treviso.

Glera is an old variety, with its former name Prosecco being derived from the village Prosecco near Trieste, where the grape in thought to have originated. It has been proposed that it was grown in Roman times and now ranks about thirtieth in importance among the country's some 2000 grape varieties.

Prosecco was traditionally used as the name for both the grape variety and the sparkling wine produced primarily from it. Prosecco di Conegliano-Valdobbiadene, Prosecco di Conegliano and Prosecco di Valdobbiadene all had DOC status, and there was also an IGT zone surrounding it. When the higher DOCG status was sought for Prosecco di Conegliano e Valdobbiadene, it became a complication that the grape and the protected designation of origin had the same name. To resolve the issue, the old synonym Glera was officially adopted for the variety as the same time as the DOCG was approved in 2009. The change was also made to reduce the possibility of sparkling wines of other origin being labeled as 'Prosecco' by using the grape variety's name. The name change is a move along the lines of the reservation of the term champagne only for wines made in the Champagne region of France.

Glera is a white grape with lower acidity levels, and generally grown in warmer climates than those varieties used for methode traditionelle. Grapes with lower acid levels are said to be softer as a result of the lighter body feel that is sensed from the reduced grape structure. It is this softer structure that is precisely what is appreciated about Prosecco.