Baix Llobregat (Catalan pronunciation: [ˈbaʒ ʎuβɾəˈɣat]) is a comarca (county) on the coast of Catalonia, Spain.

It is located in the Barcelona region and its capital is Sant Feliu de Llobregat.

It has long been proposed to split the northern part of Baix Llobregat into a separate comarca.

The Catalan government's "Report on the revision of Catalonia's territorial organisation model" (the Roca Report [ca]), published in 2000, recommends many changes to comarcas, including the creation of Baix Llobregat Nord [ca], with its capital at Martorell, taking in several more municipalities from Alt Penedès, Anoia, Bages, and Vallès Occidental.

[2] Recent campaigns have referred to the proposed new comarca as "Montserratí", due to the landmark Montserrat mountain marking part of its eastern border.