He studied theology at the University of Leipzig, where in 1826 he received his habilitation. In 1829 he was appointed associate professor, and in 1838 became a full professor of theology at Leipzig. From 1845 onward, he was head of the Leipzig Historical and Theological Society. In 1850 he resigned his professorship and moved to Wittenberg, where he focused on private studies. In 1859 Niedner was appointed professor of historical theology at Berlin, and was also Consistorialrath to the Province of Brandenburg.
His best written effort was the highly regarded "Geschichte der christlichen Kirche" (History of the Christian Church); (1846, second edition 1866). Also, he was editor of the journal "Zeitschrift für historische Theologie" (Journal of Historical Theology).