The Sunday roast is a traditional British main meal served on Sundays (usually in the early afternoon for lunch), consisting of roasted meat, roast potato or mashed potato, with accompaniments such as Yorkshire pudding, stuffing, vegetables and gravy.

It is popular throughout the United Kingdom, the United States, Canada, Australia, New Zealand and Ireland. Other names for this meal are cooked dinner, Sunday dinner, Sunday lunch, Sunday tea, Roast dinner, Sunday Roast and Sunday joint. Joint being a word that specifically refers to the joint of meat. The meal is often comparable to a less grand version of a traditional Christmas dinner in these cultures.

There are (at least) two opinions on the origins of the Sunday Roast. One holds that, during the industrial revolution, Yorkshire families left a cut of meat in the oven before going to church on a Sunday morning, which was then ready to eat by the time they arrived home at lunchtime. The second opinion holds that the Sunday Roast dates back to medieval times, when the village serfs served the squire for six days a week. Then on the Sunday, after the morning church service, serfs would assemble in a field and practice their battle techniques and were rewarded with a feast of oxen roasted on a spit.

Sunday (ⁱ/ˈsʌndeɪ/ or /ˈsʌndi/) is the day of the week between Saturday and Monday. For most Christians, Sunday is observed as a day for worship of God and rest, due to the belief that it is Lord's Day, the day of Christ's resurrection.

Sunday is a day of rest in most Western countries, part of 'the weekend'. In most Muslim countries, and Israel, Sunday is a working day.

According to the Hebrew calendars, traditional Christian calendars, Sunday is literally the "first day" of the week. According to the International Organization for Standardization ISO 8601 Sunday is the seventh and last day of the week.

No century in the Gregorian calendar starts on a Sunday, whether its first year is '00 or '01. The Jewish New Year never falls on a Sunday. (The rules of the Hebrew calendar are designed such that the first day of Rosh Hashanah will never occur on the first, fourth, or sixth day of the Jewish week; i.e., Sunday, Wednesday, or Friday).

The English noun Sunday derived sometime before 1250 from sunedai, which itself developed from Old English (before 700) Sunnandæg (literally meaning "sun's day"), which is cognate to other Germanic languages, including Old Frisian sunnandei, Old Saxon sunnundag, Middle Dutch sonnendach (modern Dutch zondag), Old High German sunnun tag (modern German Sonntag), and Old Norse sunnudagr (Danish and Norwegian søndag, Icelandic sunnudagur and Swedish söndag). The Germanic term is a Germanic interpretation of Latin dies solis ("day of the sun"), which is a translation of the Ancient Greek heméra helíou. The p-Celtic Welsh language also translates the Latin "day of the sun" as dydd Sul.