Some of the earliest inhabitants of the area were the mysterious Leghoya people. Not much is known about them, but ruins of their settlements dating back to c.1400 can found in the area. Modern Ermelo was founded by Dutch Reformed ChurchReverend Frans Lion Cachet (1835–1899). Cachet was an outspoken preacher, who had a strong interest in evangelism to Jews, his own family having had a Jewish heritage. Cachet had met and been influenced by Hermanus Willem Witteveen from Ermelo in the Netherlands as a young man, and named the settlement in honour of Witteveen.
A congregation was started at Ermelo by Cachet in 1870, and was recognised by the 5th annual general meeting of the church in April 1872.