Viscount Mayo (Irish: Bíocunta Mhaigh Eo) is a title that has been created twice in the Peerage of Ireland, both times for members of the Bourke family.

His son Theobald, the third Viscount, was also created a Baronet in the Baronetage of Nova Scotia in c. 1638 (although there are no records of this creation in the Great Seal).

The third Viscount was executed in 1652 after being found guilty of murder by Cromwell's High Court of Justice in Connaught.

[3] The third Viscount's daughter Maud married Col. John Browne, ancestor of the Marquesses of Sligo.

[6] The title was recreated for a very distant cousin, John Bourke, 1st Baron Naas, in 1781.