Beaumont-de-Lomagne (French pronunciation: [bomɔ̃ də lɔmaɲ]; Languedocien: Bèumont de Lomanha) is a commune in the Tarn-et-Garonne department in the Occitanie region in southern France.

In 1278 the town was granted a very liberal charter of laws, by the standards of the period, defining the rights and duties of its inhabitants.

In the seventeenth century, Louis XIII besieged several cities in the south-west including Beaumont; the "Chateau de Roi" was destroyed by royal decree.

The incident ended without conflict, but Beaumont, ruined, had to pay a large fine; another plague epidemic also occurred during this event.

After sending a delegate to the Estates General, Beaumont created a revolutionary club, but from 1790 the town became part of the Haute-Garonne department and became isolated, to the advantage of Grenade, its neighbour and rival.

It retains much of its history through its old buildings: the church, its fortress – whose imposing mass dominates the town – the large market with its distinctive roof, as well as approximately fifteen private mansions, the majority of which date from the seventeenth to nineteenth centuries.