Badia del Vallès (Catalan pronunciation: [bəˈðiə ðəl βəˈʎɛs]) is a town and municipality in the province of Barcelona and autonomous community of Catalonia, Spain.

The township has its beginnings in the 1960s by a government plan aimed at creating a residential area on the outskirts of the towns of Barberà del Vallès and Cerdanyola del Vallès made up of 11,054 homes and all services relating thereto.

[2] Badia del Vallès consists of a single nucleus or body population.

Thus the swallow was chosen as the symbol of migration, while the colors of each partition represent the two original municipalities (gold for Barberà and sinople for Cerdanyola).

Badia del Vallès uses an heraldic flag which follows the same pattern as its shield, and is defined as an "Oblong flag of proportions two high by three long, two-tone yellow and green vertical stripes, with the black swallow with the white chest of the shield, height 5/7 of the cloth, centered in the middle of the partition.