Walter mac Thomas de Búrca (Walter Bourke), 3rd Mac William Íochtar (died 1440) was an Irish chieftain and noble who was lord of Lower (North) Connacht, Ireland.

The son of Thomas mac Edmond Albanach de Búrca, 2nd Mac William Íochtar (d.1402), de Búrca was succeeded by his younger brothers, Edmund na Féasóige de Búrca (4th), Tomás Óg de Búrca (5th), and Risdeárd de Búrca (6th Mac William Íochtar), and later by his sons, Theobald Bourke (8th) and Ricard Bourke (9th Mac William Íochtar).

[2][3] From the Annals of the Four Masters: