Jacobus Johannes "Koos" van Ellinckhuijzen (20 September 1942 – 6 September 2016) was a Namibian visual artist. He was most noted for his work on Namibian and South-West African postage stamps.^[1]

Van Ellinckhuijzen was born to Dutch parents on 20 September 1942 in Pretoria, the then administrative capital of the Union of South Africa. He pursued a military career but, after 11 years of service, became a game warden with the Department of Nature Conservation and Tourism in South-West Africa. Without any formal instructions in the arts he completed four paintings during that time. In 1979 he became a full-time artist.^[2]

Van Ellinckhuijzen was a surrealist exhibiting in both Namibia and the United States. His personal preference were surreal and metaphysical topics as well as three-dimensional astrophysical panoramas that he called "Stereoptic" creations. Of his stamps The solar system, Halley's comet and Satellites in orbit are well-known. The painting Nativity was awarded a first prize at a 3D arts exhibition in Rochester, NY in the United States. He is claimed to have been the first artist to manually produce stereo paintings.^[1] Adelheid Lilienthal, in Art in Namibia, noted the scientific accuracy of his designs, their clean lines and his use of watercolor techniques.^[3][4][5] Of his sources of inspiration, van Ellinckhuijzen wrote that "M. C. Escher, René Magritte and Albert Einstein [...] all left their legacies in Koos' soul".^[6]

Van Ellinckhuijzen died on 6 September 2016 in Swakopmund at the age of 73, a few days after suffering a stroke.^[7]