Natasha Sumner joined the faculty of Celtic Languages and Literatures at Harvard in 2015. She originally hails from Canada, where she was first introduced to the languages, literature, and folklore she now works with professionally. She completed her PhD at Harvard.

Lately she has been spending much of her time writing a book, under contract with Princeton University Press, about the historical development of the Gaelic narrative corpus about the hero Fionn mac Cumhaill and his roving warrior band. This narrative corpus encompasses a vast body of story and song, some of it well over a millennium old, extant in written literature and collected folklore.

She has also completed the initial stages of work on a database of modern Fenian folklore from Ireland, Scotland, the Isle of Man, and Nova Scotia. The preliminary catalog, which contains metadata for over 3,300 orally collected stories, lays, and other lore, is accessible from this website. In 2019 she initiated the Fionn Cycle Folklore Project, a major research project dedicated to creating an online Fenian folklore database, which will have its own website (and much greater searching capacity). 

She writes and speaks about various aspects of the Fenian corpus, as well as other topics pertaining to literature and folklore in Irish, Scottish Gaelic, and English. In a particularly exciting project, she completed the transcription and translation used to subtitle the recently re-discovered Irish-language film, Oidhche Sheanchais (A Night of Storytelling), directed by the great documentary film pioneer Robert Flaherty and restored by the Harvard Film Archive (2015 [1935]). For more on this project see: Harvard Film Archive LaunchIrish Film Institute Launch; co-authored article in Folklore 116 (2015).

She teaches courses on Irish and Scottish Gaelic language, post-medieval literature, and folklore.