Before European settlement, the Kaurna people called the area of modern-day Belair "piraldi".

Gustav Ludewigs, who subdivided the area, may have named the suburb after Bel Air, Martinique, being his wife Maria's birthplace.

[6] Two petitions, with 620 signatures between them, were presented to the South Australian Parliament in 1878 calling for a railway line to be constructed into the Adelaide Hills.

[6] Further campaigns to protect the land during the 1880s, as well as the greater accessibility to the farm due to the construction of the Adelaide to Nairne Railway line, led to Government Farm being transformed into Belair National Park, proclaimed on 19 December 1891 with the passage of the National Park Act.

[8] The building was renamed Hope Lodge in 1893 and operated as a training centre for missionaries until 1907, and is now part of the St. Johns Senior School campus.

Kalyra Consumptive Home was incorporated in December 1894 by the James Brown Memorial Trust, with its first patients admitted in February or March 1895.

[8] In 1915, quarries were opened at Sleep's Hill at the western end of Belair by Burt and Timms, who were contracted to build houses and roads in the nearby suburb of Colonel Light Gardens.

They made efforts to stop blasting in nearby quarries and pushed the district council to repair Belair's roads.

To the east it is bounded by Sheoak Road and the eastern edge of Belair National Park.

To the west it is bounded by Laffers Road, Gratton Street, Neate Avenue, Gum Grove, Watiparinga Reserve, and the Belair railway line.

The facilities in the park include walking and mountain biking trails, tennis courts, and ovals with cricket pitches and Australian rules football goalposts.

It is also home to Old Government House and State Flora, the oldest plant nursery in South Australia.

The most commonly stated religious affiliations in the 2021 census were Anglican (11.1%), Catholic (9.5%), and the Uniting Church (5.9%).