Valentí Almirall i Llozer (Catalan pronunciation: [bələnˈti əlmiˈɾaʎ]; Barcelona, Catalonia, Spain, 8 March 1841 – 1904) was a Catalan politician, considered one of the fathers of modern Catalan nationalism, and more specifically, of the left-wing variety.
Catalan nationalism promotes the idea that the Catalan people form a distinct nation and national identity. A related term is Catalanism (Catalan: catalanisme, Spanish: catalanismo), which is more related to regionalism and tends to have a wider meaning; most people who define themselves as Catalanist do not necessarily identify as Catalan nationalists.
Intellectually, modern Catalan nationalism can be said to have commenced as a political philosophy in the unsuccessful attempts to establish a federal state in Spain in the context of the First Republic (1873-1874). Valentí Almirall i Llozer and other intellectuals that participated in this process set up a new political ideology in the 19th century, to restore self-government, as well as to obtain recognition for the Catalan language. These demands were summarized in the so-called Bases de Manresa in 1892.