Eleven new species of crustose, lichenized fungi are described from the Falkland Islands (Islas Malvinas). Nine species are saxicolous, whereas Lecania vermispora occurs on the stems of Hebe elliptica and Tephromela lignicola is lignicolous on fence posts. The new species are: Bacidia marina, with a sordid blue-green K−, N+ violet epihymenium and acicular, multiseptate ascospores; B. pruinata, with pruinose apothecia and multiseptate ascospores; Buellia gypsyensis, with a thallus containing 5-O-methylhiascic acid and with Amandinea-type conidia; Cliostomum albidum, with pruinose apothecia lacking pigments; C. longisporum, with long narrow ascospores (c. 20 × 3 µm); Coccotrema rubromarginatum, with a placodioid thallus having a red-brown margin and lower surface; Hymenelia microcarpa, with minute, immersed apothecia (<0·1 mm diam.) and a trebouxioid photobiont; Lecania vermispora, with vermiform, 3–6 septate ascospores; Lepra argentea, with papillate isidia with dark caps; Rhizocarpon malvinae, which is similar to R. reductum but with a grey thallus, generally sessile apothecia with a thick raised margin and often with the Cinereorufa-green pigment in the epithecium and upper exciple; and Tephromela lignicola, a sterile, sorediate species on fence posts. Most of these species are reported only from the Falkland Islands although Coccotrema rubromarginatum is also reported from Isla de los Estados and Isla Grande de Tierra del Fuego, Argentina. Ascoconidia are reported from Lepra argentea and cephalodia from Pertusaria pachythallina. Keys to the species reported from the Falkland Islands in the genera of the newly described species are also provided.