Ritter received an excellent education in the natural sciences and was well versed in history and theology. Guided by the educational principles of the famed Swiss teacher Johann Heinrich Pestalozzi and by the ideas of the German philosopher-theologian Johann Gottfried von Herder on the relation between man and his environment, Ritter became a teacher and philosopher in the field of geography, serving as professor at the University of Berlin from 1820 until the end of his life.

Viewing geography as an empirical science, he maintained that its methodology required proceeding from one observation to the next, not from opinion or hypothesis to observation. Though he was convinced that there were laws of geography, he appeared to attach no particular importance to establishing them clearly. He stressed, instead, the importance of utilizing all the sciences to delineate the nature of geography, which was, in his view, unique.

Ritter always regarded Humboldt, who was ten years his senior, as his master and partly based his geographical writings on Humboldt's ideas. He was frequently more a historian than a geographer and wrote what has come to be known as a geographical interpretation of history. The opposition to his ideas that developed after his death arose in part from the contention that he had made geography ancillary to history. Even so, during his later life and for nearly 20 years following his death, his ideas deeply influenced geographical research in Germany.

His first geographical writings, on Europe, were published in 1804 and 1807. His great work, Die Erdkunde im Verhältniss zur Natur und zur Geschichte des Menschen (“Earth Science in Relation to Nature and the History of Man”), was intended as a world survey but was never completed. The first volume, on Africa, was published in 1817 and brought him his appointment at the University of Berlin; a revised edition appeared in 1822. Between 1832 and his death he regularly published new volumes, chiefly on Asia. The work, though incomplete, ran to 20,000 pages in 19 volumes.