Forbasach mac Ailella
Forbasach mac Ailella was a King of Osraige in modern County Kilkenny. He ruled from 735 to 740.
His genealogy is not recorded in Rawlinson Genealogies; the annals record only that he was slain but give no details. His son Fáelán mac Forbasaig was a King of Osraige.
The Book of Leinster king lists an Ailill mac Fáeláin as king prior to Cellach mac Fáelchair. This Ailill would be the brother of Cú Cherca mac Fáeláin and son of Fáelán mac Crundmaíl, previous kings.