Clann Cholmáin is the dynasty descended from Colmán Már (Colmán Már mac Diarmato), son of Diarmait mac Cerbaill. Part of the Southern Uí Néill — they were the kings of Mide (Meath) — they traced their descent to Niall Noígiallach and his son Conall Cremthainne.
Related dynasties descended through Conall Cremthainne and Diarmait mac Cerbaill included the Síl nÁedo Sláine, the kings of Brega, descended from Colmán Már's youngest brother Áed Sláine, and the less important Clann Cholmáin Bicc (or the Caílle Follamain), descendants of the middle brother, Colmán Bec. The Kings of Uisnech, among others, belonged to Clann Cholmáin.
Important kings of Clann Cholmáin include: