Domnall mac Donnchada Midi (died 799) was a King of Mide of the Clann Cholmáin.
The period between the death of Donnchad Midi and the accession of his son Conchobar mac Donnchado in 803 was a time of civil strife and confusion amongst the Clann Cholmáin.
Apparently Donnchad was succeeded by his son Domnall mac Donnchada Midi in 797.
That same year the high king Áed Oirdnide of the Cenél nEógain invaded Meath and defeated Clann Cholmáin at the Battle of Druim Ríg.
[2] Áed went on to devastate Meath which submitted to him and the beginning of his high kingship is considered to have occurred from that point on.