Albert (Latin Albertus; c. 1268 – 22 September 1318), called the Fat (pinguis), was a member of the House of Welf, one of the oldest European noble families.
He was first under guardianship of his uncle, Conrad, Prince-Bishop of Verden, and then of his elder brother, Henry I, Duke of Brunswick-Lüneburg.
In 1286 the three brothers divided their father's Principality of Wolfenbüttel; Albert received the areas around Göttingen, Minden, Northeim, Calenberg, and Hanover.
In 1292, the third brother, William, died childless, and Albert and Henry, who had received the Principality of Grubenhagen, quarrelled about William's share, the remaining belittled areas around Brunswick and Wolfenbüttel; Albert finally prevailed.
On 10 January 1284 Albert married Rixa, daughter of Henry I, Prince of Werle and Mecklenburg-Güstrow, and Rikissa Birgersdotter.