Áed Ua Crimthainn (fl. 12th century), also called Áed mac Crimthainn, was abbot and coarb of Terryglass (Tir dá Glas), near Lough Derg in County Tipperary, Ireland. He was the principal scribe of the Book of Leinster (Middle Irish: Lebar na Núachongbhála), the Book of Oughaval, an important Middle Irish medieval illuminated manuscript, and is also believed to have been its sole compiler. Áed signed himself Áed Ua Crimthainn.