Plaatje was born in Doornfontein near Boshof, Orange Free State (now Free State Province, South Africa), the sixth of eight sons. His grandfather's name was Selogilwe Mogodi (1836-1881) but his employer, the Boer farmer Groenewald, nicknamed him Plaatje ('Picture') in 1856 and the family started using this as a surname. His parents Johannes and Martha were members of the Tswana nation. They were Christians and worked for missionaries at mission stations in South Africa. When Solomon was four, the family moved to Pniel near Kimberley in the Cape Colony to work for a German missionary, Ernst Westphal, and his wife Wilhelmine. There he received a mission-education. When he outpaced fellow learners he was given additional private tuition by Mrs. Westphal, who also taught him to play the piano and violin and gave him singing lessons. In February 1892, aged 15, he became a pupil-teacher, a post he held for two years.