Martinus Johannes "Tinus" de Jongh (Amsterdam, 1885 – Bloemfontein, 1942) was one of South Africa's most popular painters. Self-taught, he started out as a decorator in the Netherlands before devoting himself fully to painting. He gained some recognition when the Stedelijk Museum in Amsterdam bought one of his early pictures.
He arrived in South Africa in 1921 with a sober style rooted in the Dutch tradition, exemplified there by Still Life with Birds and Hare. The South African light and landscape soon led him to give up his muted palette for more saturated colours. His Cape scenes, with gabled farmhouses, were in such demand that he eventually traded his considered brushwork for a broader palette-knife technique.
His etchings sold in the hundreds through his dealer Louis Woolf. He died of lung cancer in Bloemfontein in 1942. He had married Johanna Maria Verhoef in 1911 and they had three children; Gabriel de Jongh also became a landscape painter in South Africa.