A bedsit, bedsitter, or bed-sitting room is a form of accommodation common in some parts of the United Kingdom which consists of a single room per occupant with all occupants typically sharing a bathroom. Bedsits are included in a legal category of dwellings referred to as houses in multiple occupation (HMO).

Bedsits arose from the subdivision of larger dwellings into low-cost accommodation at low conversion cost. In the UK, a growing desire for personal independence after World War II led to a reduced demand for traditional boarding houses with communal dining. Bedsits are often occupied by young single people, students, those unable to purchase their own properties, or those whose occupation is of a transitory nature; the cost is typically lower than for other types of property. Someone whose employment is a long distance from their home may sometimes rent a bedsit to reduce the cost and inconvenience of daily travel.

The American and Canadian equivalents to a bedsit are rooming houses and single room occupancy (SRO); however, in Canada those differ from bedsits in that rooming houses and SRO hotels generally do not provide tenants with private kitchen or bathing facilities; instead, those facilities are shared. True bedsits are rare in Canada but are found in some Atlantic regions, such as the city of St. John's.

In the United States, single room apartments are typically called a studio apartment, or when slightly smaller an efficiency apartment, also known simply as an efficiency.

The Australian equivalent to bedsit is called flatette. In New Zealand, the terms bedsit and granny flat are used interchangeably.^{[citation needed]}

A bedsit can also be compared to a Soviet communal apartment, in which a common kitchen, bathroom, toilet, and telephone are shared by several families, each of which lives in a single room opening up onto a common hallway.^{[citation needed]}

In Nigeria, an analogue to a bedsit is a face-to-face apartment building, where a group of one- or two-room apartments have entrances facing each other along a walkway leading to the main entrance of the building in which the apartments are located. The apartments, which often have shared bathrooms and kitchen spaces, are low-rent and are commonly used by low-income residents because of their affordability.

Bedsits were once common in Dublin and other towns in Ireland, although they had been impractical to implement after the introduction of planning permission in 1963. Bedsits were banned in 2008 by the Housing (Standards for Rented Houses) Regulations 2008, with a phase-out date of February 2013. The Health Service Executive and approved housing bodies can still offer equivalent accommodation, which is mostly used as emergency accommodation for the homeless. In 2013, regulations came into force in Ireland, under which landlords were obliged to provide each tenant with a separate bathroom, a four-ring cooker, and access to laundry facilities and other basic facilities, or risk being fined up to €5,000. Bedsits have since been outlawed in the Republic.