William "the Blind Abbot" Bourke, 20th Mac William Íochtar (Irish: William An tAb Caoch Bourke; English: /bɜːrk/; BURK; died 1593) was an Irish chieftain and noble.

His brother was Richard "the Iron" Bourke, 18th Mac William Íochtar (d.1583).

He succeeded his cousin, Richard Bourke, 19th Mac William Íochtar (d.1586) a great-grandson of Ricard Ó Cuairsge Bourke, 7th Mac William Íochtar (d.1479).

William was succeeded by his cousin, Tibbot MacWalter (Theobald Fitzwalter) Kittagh Bourke, 21st Mac William Íochtar (c.1570–c.1602), the eldest child of Walter Kittagh Bourke (d.1591) and grandson of Seaán mac Oliver Bourke (Sir John Bourke), 17th Mac William Íochtar and 1st Baron Ardenerie (d.1580).

[2] This biography of an Irish noble is a stub.