HITZACKER, a town of Germany, in the Prussian province of Hanover at the influx of the Jeetze into the Elbe, 33 m. N.E. of Lüneburg by the railway to Wittenberge. Pop. (1905) 1106. It has an Evangelical church and an old castle and numerous medieval remains. There are chalybeate springs and a hydropathic establishment in the town. The famous library now in Wolfenbüttel was originally founded here by Augustus, duke of Brunswick (d. 1666) and was removed to its present habitation in 1643.