Abbacchio (Italian: [abˈbakkjo]) is an Italian preparation of lamb typical of the Roman cuisine. It is consumed throughout central Italy as an Easter and Christmas dish. Abbacchio is a product protected by the European Union with the PGI mark.

In Romanesco dialect, the offspring of the sheep who is still suckling or recently weaned is called abbacchio, while the offspring of the sheep almost a year old who has already been shorn twice is called agnello (lit. 'lamb'). This distinction exists only in the Romanesco dialect.

There are disagreements regarding the origin of the term:

Throughout central Italy, including Sardinia, pastoralism was the main source of meat. Since ancient times, abbacchio has been one of the staple foods of the Lazio region, especially for rural communities, whose consumption at the table was considerable. The tradition of consuming abbacchio spread in ancient times where mainly adult sheep were slaughtered.

The slaughter of abbacchio was forbidden except during the Easter and Christmas periods, and until June. Over the centuries, given the importance of the food, around 100 recipes for preparing lamb have been developed in Lazio.

Given the importance of abbacchio in social life, historical events dedicated to abbacchio are still organized in the Lazio region today, i.e. sagre, country festivals and popular events. In ancient times, sheep was eaten during work in the countryside, while abbacchio was consumed only during the Easter holidays.

According to the classification of Sardinian Lamb PGI, abbacchio is a suckling lamb that is a little over a month old and up to 7 kg (15 lb) in weight. Slaughter must be carried out on male or female lambs between 28 and 40 days of age.

In Roiate, comune (municipality) in the Metropolitan City of Rome Capital located about 45 kilometres (28 mi) east of Rome, the Sagra dell'abbacchio, celebrating this dish, is organized annually. Abbacchio is a product protected by the European Union with the PGI mark.