The bay-and-gable is a distinct residential architectural style that is ubiquitous in the older portions of Toronto, Ontario, Canada. The most prominent feature of the style is a large bay window that usually covers more than half the front façade of the home, surmounted by a gable roof. The bay window typically extends from the ground level towards the roof, although a variant of the housing form exists where the bay window fronts only the first level; known as a half-bay-and-gable. The housing form may be built as a stand-alone structure, although it is more often built as a semi-detached, or as terraced houses.
The form emerged during the 1860s, with architects adopting elements commonly associated with English villas and Gothic-styled buildings due to their popularity with residents during that period. As the city underwent significant population growth in the latter half of the 19th century, scaled versions of the bay-and-gable design were built by developers as they proved to be efficient housing forms that could be built at a pace that kept up with Toronto's population growth. The housing form was also popular amongst homeowners who sought more ornamentations on their homes, with the gables and large windows providing areas that could be decorated with minimal investment. A large number of bay-and-gable homes were built until the late 1890s when it was supplanted by other housing styles.
The housing form re-emerged in the late 20th and early 21st century, with several residential developments within the city and the Greater Toronto Area being infilled with bay-and-gable variants.