Bernard (between 1358 and 1364 – 11 June 1434) was Duke of Brunswick-Lüneburg in the early 15th century, co-ruling Brunswick with his younger brother Henry the Mild from 1400 to 1409, then as sole ruler of Brunswick from 1409 to 1428 and of Lüneburg from 1428 until his death in 1434.

Bernard was the second son of Magnus II, Duke of Brunswick-Luneburg.

After the death of his father in 1373, he and his brothers agreed with the Ascanian dukes of Saxony-Wittenberg to alternate rule in the Principality of Lüneburg.

After his elder brother Frederick was murdered in 1400, Bernard and Henry the Mild began a revenge campaign against the Archbishopric of Mainz and the County of Waldeck, since the archbishop of Mainz was the suspected instigator of the murder plot and the Count of Waldeck performed the deed.

Bernard married Margaret, daughter of Wenceslaus, Elector of Saxony, in 1386.