A long weekend is a weekend that is at least three days long (i.e. a three-day weekend), due to a public or unofficial holiday occurring on either the following Monday or the preceding Friday.

Many countries also have four-day weekends, in which two days adjoining the weekend are holidays. Examples are Good Friday / Easter Monday, and Christmas Day / Boxing Day (e.g. when Christmas Day occurs on a Thursday or Monday).

In many countries, when a lone holiday occurs on a Tuesday or a Thursday, the day between the holiday and the weekend may also be designated as a holiday, set to be a movable or floating holiday, or work/school may be interrupted by consensus unofficially. This is typically referred to by a phrase involving "bridge" in many languages; for example in some Spanish-speaking countries the term is puente ("bridge") or simply "fin de semana largo".

Four-day bridge weekends are commonplace in non-English speaking countries, but there are only a couple of examples in English-speaking countries:

In the United States, the fourth Thursday of November is Thanksgiving, a public holiday on which most workplaces are closed; many workplaces remain closed the following day to create a four-day weekend.

In Melbourne, Australia, the Melbourne Cup holiday is held on a Tuesday. The Monday is not a public holiday, but many people modify their work arrangements to also have the Monday off and many schools will have a "pupil free day", so it is colloquially referred to as the "Cup Day long weekend".

In Flanders, the Dutch-speaking part of Belgium, "brugdag" ("bridge" day) is used. In the Netherlands also "Klemdag" is used.

In France, a bridge idiom is used: faire le pont ("to make the bridge") is used to mean taking additional holiday days. For example, if there is already an official holiday on Thursday, one could "faire le pont" on the Friday and thus have a four-day weekend (Thursday through Sunday inclusive).