Friedrich Rittelmeyer (5 October 1872, Dillingen an der Donau, Bavarian Swabia – 23 March 1938, Hamburg) was a Lutheran German minister, theologian and the principal founder and first leader of The Christian Community.
Rittelmeyer came to prominence in the early 20th century as a leading academic liberal theologian and priest in Germany and wrote several books that advocated a socially engaged "Christianity of deeds" (Tatchristentum).
Rittelmeyer worked and closely collaborated with Christian Geyer (1862–1929), the head preacher of the Sebalduskirche, and the pair produced two joint volumes of sermons.
At first gripped by nationalist enthusiasm, he soon came to oppose the First World War and with 4 other Berlin theologians signed a proclamation of peace and understanding on the occasion of Reformation Day (October 1917).
Under National Socialism, he carried out a permanent balancing act: between critical intellectual discussion with Nazism in numerous publications on the one hand and his task of enabling a survival strategy for the Christengemeinschaft (for which he felt responsible) on the other.