Conchobar 'Buidhe' Mág Tighearnán (anglicised Conor 'The Tawny' McKiernan) was chief of the McKiernan Clan and Baron or Lord of Tullyhunco barony, County Cavan from 1312 until 1314.
Conchobar was the son of Gíolla Íosa 'Leith' Mág Tighearnán, son of Sithric 'Carrach-in-Cairn' Mág Tighearnán (d.1290), son of Duarcán Mág Tighearnán, the Second (d.1290), son of Íomhaor Mág Tighearnán, the Second (died c.1269), son of Tighearnán, son of Duarcán the First, son of Íomhaor the First, son of Gíolla Chríost, son of Amhlaoibh, son of Tighearnán, the founder of the clan. His grandfather Sithric 'Carrach-in-Cairn' Mág Tighearnán had been a previous chief of the clan. Conchobar's brothers were Matha Mág Tighearnán (d. 1311) a former chief of the clan, Domhnall 'An Saithnech' Mág Tighearnán (d.1312) whom he succeeded as chief, Tomás Mág Tighearnán (d.1358) who was also a chief of the clan, Duarcán, Cú Chonnacht, Cormac, Fergal 'Cend Craiche' and Mathghamhain (d. 1314).
Conchobar's nickname 'Buidhe' meant that he had had either blonde hair or an olive complexion.
On the death of the previous chief, his brother Domhnall 'An Saithnech' Mág Tighearnán in 1312, Conchobar took the chieftaincy and resided in the castle of Croaghan of the Cups (Irish- Cruachan O'Cúbhrán), besides the modern town of Killeshandra.
Conchobar was murdered in 1314 in the Battle of Kilmore, County Cavan. His brother Mathghamhain and many other McKiernans were also killed in the battle. Some of the annals give a later date for Conchobar's death.