Mac Brádaigh is an Irish surname, meaning "spirited".
[1] The MacBrádaigh family were a strong sept of Breifne, in what is now County Cavan.
Chiefs of Cúil Bhríghde feature in the Annals of Ireland, for example in the 'Annals of the Four Masters'.
In 1890 in County Cavan, Brady had the third highest number of births registered.
A separate family, the Ó Grádaigh, of north-east Thomond, generally anglicise their name as O'Grady, but some have also used the name Brady.