A Sunday strip is a newspaper comic strip format, where comic strips are printed in the Sunday newspaper, usually in a special section called the Sunday comics, and virtually always in color. Some readers called these sections the Sunday funnies. Some newspapers, such as Grit, published Sunday strips in black-and-white, and some (mostly in Canada) print their Sunday strips on Saturday.

Subject matter and genres have ranged from adventure, detective and humor strips to dramatic strips with soap opera situations, such as Mary Worth. A continuity strip employs a narrative in an ongoing storyline. Other strips offer a gag complete in a single episode, such as Little Iodine and Mutt and Jeff.

The Sunday strip is contrasted with the daily comic strip, published Monday through Saturday, usually in black and white. Many comic strips appear both daily and Sunday, in some cases, as with Little Orphan Annie, telling the same story daily and Sunday, in other cases, as with The Phantom, telling one story in the daily and a different story in the Sunday. Some strips, such as Prince Valiant appear only on Sunday. Others, such as Rip Kirby, are daily only and have never appeared on Sunday.

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.