Founded in 1882 as the Martorell Museum [es], since 2011 it comprises four other locations: its main site at the Forum Building, the Historical Botanical Garden of Barcelona [es], the Botanical Garden of Barcelona, and the Laboratori de Natura [ca].

The museum was created in 1882 following the bequest, patronage and will and testament of a local business broker, Francesc Martorell Peña (1822–1878), who left on this purpose to the city of Barcelona his personal archaeological and natural history collections.

Another building that is also located in the Parc de la Ciutadella, the nearby Castle of the Three Dragons, built in 1888 for the Barcelona Universal Exposition, was assigned to the Museum of Natural Sciences of Barcelona in 1917 and started exhibiting the zoological collections as of 1920.

At first called el Museu Blau[6] (Catalan for 'the Blue Museum'), the Forum Building changed its allocated function name to the official name of the institution (Museum of Natural Sciences of Barcelona) in December 2017.

[7] Since 2011, the merge of the above-mentioned entities reached the number of five different sites, all of them recognised as official seats by the museum: