Detailed pollen records, derived from thick Late-glacial and post-glacial sediments collected at An Loch Mór, a small but deep lake on Inis Oírr, Aran Islands, western Ireland provide new insights into post-glaciation, higher-plant colonisation in Ireland. In general, tall shrubs, including juniper and birch (other than Betula nana), did not survive the Younger Dryas cold period (c.12.85-11.65 ka, i.e. calibrated years BP) on Inis Oírr. Most woody species that subsequently constituted the post-glacial flora, spread, established and expanded during the Holocene. The sequence of establishment and expansion of woody plants in the early Holocene was juniper, followed by birch, then hazel and finally tall canopy trees, i.e. pine, and then oak and elm more or less simultaneously. There are substantial records for tall shrubs including Viburnum opulus and Rhamnus cathartica. The rather open character of the early post-glacial, tall-canopy woodlands is noteworthy. This favoured high biodiversity and provided refugia for shade-sensitive woody and herbaceous species. The spread and expansion of alder, ash and yew are also discussed. For much, and possibly all of the post-glacial period, Inis Oírr was an island isolated from nearby land masses by the Atlantic Ocean but this seems not to have influenced plant spread. As in the case of Ireland itself, island status seems to have had little influence on Holocene plant-colonization patterns and processes.