Reverend Johann Heinrich Schmelen, born Johann Hinrich Schmelen (7 January 1776 – 26 July 1848) was a German missionary and linguist who worked in South Africa and South-West Africa. Traveling through the area of today's northern South Africa and central and southern Namibia he founded the mission stations at Bethanie and Steinkopf and discovered the natural harbour at Walvis Bay. Together with his wife Zara he translated parts of the Bible into Khoekhoegowab (Damara/Nama) and published a dictionary.
Schmelen was born into a middle-class family on 7 January 1776 in Kassebruch, today a suburb of Hagen im Bremischen in the German state of Lower Saxony. To evade conscription he went to London where was influenced by pastors of the German congregation. He wanted to become a missionary and was advised to attend the missionaries' seminary of pastor Jänicke in Berlin.
After graduation he was sent to South Africa in 1811. He accompanied Christian Albrecht to Pella in the Northern Cape from where he traveled the Oranje to serve a number of small nomadic pastoral tribes.
In 1812 Schmelen was ordered to trek into Namaland to found a missionary station near the Atlantic coast. He joined a group of Nama and Orlam on their way to ǀUiǂgandes. They arrived in 1814, and Schmelen named the place Bethanie. He then traveled further north until approximately 22 degrees latitude but returned and founded a missionary station for Amraal Lambert's clan of the Kaiǀkhauan (Khauas Nama) people.