Ten new species in nine different genera are described from the Falkland Islands (Islas Malvinas): Bryonora granulata with a finely granular thallus containing perlatolic acid; Bryoria mariensis, a terricolous species with norstictic acid and unusual cortex cells; Carbonea hypopurpurea with a K+ purple hypothecium and a thallus containing confluentic and 2′-O-methylperlatolic acids; Caloplaca megalariicola lichenicolous on Megalaria grossa; Cladonia flammea with a red-orange coloration on the lower side of the primary squamules; Cliostomum falklandicum, on rocks and with a dispersed thallus containing only atranorin; Lepraria malouina with usnic and stictic acids; Rimularia andreaeicola, over bryophytes and lacking lichen substances; R. subpsephota, similar to R. psephota but with a discrete white thallus lacking norstictic acid; and Usnea austrocampestris, a straggling species in sect. Neuropogon from the mountain tops. Rimularia andreaeicola is also known from Tierra del Fuego and R. subpsephota from Tierra del Fuego and South Georgia, but the other species are known only from the Falkland Islands. The new combinations Carbonea agellata, C. subdeclinans, Cliostomum aeruginascens and C. violascens are also made; Lecidea interrupta Darb. and Lecidea protracta Darb. are reduced to synonymy with Lecanora xantholeuca (Müll. Arg.) Hertel; Rhizocarpon simillimum is reported for the first time from the Southern Hemisphere, from the Falkland Islands and New Zealand; and Bryoria chalybeiformis is reported for the first time from the Falkland Islands.