Oswald (c 604 – 5 August 642) is King of Northumbria from 634 until his death, and is venerated as a saint in the Middle Ages.

Oswald is the son of Æthelfrith of Bernicia and comes to rule after spending a period in exile; after defeating the British ruler Cadwallon ap Cadfan, Oswald brings the two Northumbrian kingdoms of Bernicia and Deira once again under a single ruler, and promotes the spread of Christianity in Northumbria.

He is given a strongly positive assessment by the historian Bede, writing a little less than a century after Oswald's death, who regards Oswald as a saintly king; it is also Bede who is the main source for present-day historical knowledge of Oswald.

After eight years of rule, in which he is the most powerful ruler in Britain, Oswald is killed in the Battle of Maserfield.