A pig roast or hog roast is an event or gathering which involves the barbecuing of a whole pig. Pig roasts, under a variety of names, are a common traditional celebration event in many places including the United Kingdom, Philippines, Puerto Rico and Cuba. It is also popular in the United States, especially in the state of Hawaii (a luau) and in the Southern United States (whole hog barbecue and pig pickin'). In Southeast Asia, a pig roast is a staple among the Buddhist, and Christian communities, notably among Catholic Filipinos and Hindu Balinese people, or Buddhist Chinese people.

The tradition of the hog roast goes back millennia and is found in many cultures. There are numerous ways to roast pork, including open fire rotisserie style roasting, and "caja china" style box grilling. Many families traditionally have a pig roast for Thanksgiving or Christmas. In Miami and other areas with large Cuban, Puerto Rican, Honduran or other Caribbean populations pig roasts are often held on Christmas Eve by families and friends, whereas families from Hawaii often hold a roast on Memorial Day.

In Indonesia, roast pig (using both adult or suckling pig) is called babi guling, babi putar, babi panggang or babi bakar; it is predominantly found in non-Muslim majority regions, such as Hindu Bali and Christian Batak lands in North Sumatra, the Minahasa people of North Sulawesi, Toraja in South Sulawesi, Papua, and also among Chinese Indonesians. In Bali, babi guling is usually served with lawar and steamed rice; it is a popular dish in Balinese restaurants and warungs. In the Batak people's tradition, babi guling is a prerequisite in wedding offerings by the bride's family. In Papua, pigs and yams are roasted in heated stones placed in a hole dug in the ground and covered with leaves; this cooking method is called bakar batu (burning the stone), and it is an important cultural and social event among Papuan people.

In most regions of the Philippines, whole-roasted pig is known by the Spanish-derived term lechón (usually spelled lechon without diacritics, but also litson or lichon). It is traditionally prepared throughout the year for special occasions, festivals, and the holidays. Although it acquired the Spanish name, Philippine lechon has pre-Hispanic origins as pigs are one of the native domesticated animals of all Austronesian cultures and were carried throughout the Austronesian Expansion to Polynesia. It differs from Spanish and Latin American lechón in its ingredients, preparation, and the fact that it uses adult pigs. It is most similar to neighboring native dishes like the Balinese babi guling (though differing in the stuffing and spices used). It is considered one of the unofficial national dishes of the Philippines.

The native name of Filipino lechón is inihaw [na baboy] in Tagalog, a general term meaning "charcoal-roasted/barbecued [pig]". Native names were also preserved in other regions until recently, like in Cebu where it was previously more commonly known as inasal until Tagalog influence changed it to lechon in the 2000s. Roasted suckling pigs are differentiated as "lechon de leche" (which in Spanish would be a linguistic redundancy). The dish that is explicitly derived from the Spanish lechón style of cooking is known as cochinillo (from cochinillo asado). Unlike native Filipino lechons, cochinillo uses a suckling pig that is splayed and roasted in an oven. The term lechon has also become generalized as a loanword for anything spit-roasted over coals. It is also used for other Filipino dishes like lechon manok (native roasted chicken) , lechon belly (only the pork belly), and lechon baka (a whole cow spit-roasted Filipino-style), thus lechon made from whole pig is differentiated as "lechon baboy" (literally "pig lechon").

There are two major methods of preparing lechon in the Philippines, the "Manila lechon" (or "Luzon lechon"), and the "Cebu lechon" (or "Visayas lechon").

Visayan lechon is prepared stuffed with herbs which usually include scallions, bay leaves, black peppercorn, garlic, salt, and distinctively tanglad (lemongrass) or leaves from native Citrus trees or tamarind trees, among other spices. A variant among Hiligaynon people also stuffs the pig with the sour fruits of batuan or binukaw (Garcinia binucao). It is usually cooked over charcoal made from coconut husks. Since it is already flavored with spices, it is served with minimal dipping sauces, like salt and vinegar or silimansi (soy sauce, calamansi, and labuyo chili).

Luzon lechon on the other hand, is typically not stuffed with herbs. When it is, it is usually just salt and pepper. Instead, the distinctiveness of Manila lechon comes from the liver-based sauce, known as the "lechon sauce". Lechon sauce is made from vinegar, brown sugar, salt, pepper, mashed liver (or liver spread), breadcrumbs, garlic and onion. Manila lechon is also typically cooked over woodfire.