The Battle of St. Jakob an der Birs, fought near Basel in Switzerland on 26 August 1444, was a battle of the Old Zürich War.
In 1443, the seven cantons of the Old Swiss Confederacy invaded the canton of Zürich and beseiged the city. Zürich had made an alliance with Frederick III, Holy Roman Emperor, and Frederick appealed to Charles VII of France to send an army to relieve the siege.
Charles, seeking to send away troublesome troops made idle by the truce with Henry VI of England in the Hundred Years' War, sent his son the Dauphin (later Louis XI of France) with an army of about 40,000 mercenaries into Switzerland. At St Jakob an der Birs near Basel they were stopped by a Swiss force of 1,600 soldiers. The Swiss were wiped out in the battle that followed, but inflicted so many casualties (8,000 killed) on the French that they withdraw.