Martinus Johannes de Jongh is considered one of South Africa’s most popular oil painters. He was born in Holland, where he studied Decorating at the Ambachtschool in Amsterdam. It was here that he learned painting techniques. Whilst working as a decorator, he also painted local street scenes and landscapes in the style of the Dutch Impressionists.

In 1921 he moved to South Africa, where he continued to produce oil paintings of his surroundings. After a successful exhibition in 1923, he was able to purchase a car which enabled him to travel and see more of the local landscape. He responded to the effect of light on the landscape and began to change his palette to include more saturated colours. Tinus de Jongh is best known for his dramatic portrayal of rugged mountainous landscapes, often including a Cape farmhouse. He developed a painting technique using a palette knife placing wet light-coloured paint onto wet dark paint. This technique enabled him to work swiftly and resulted in a prolific output. Tinus de Jongh is also highly considered for a significant number of etchings of South African buildings of historical importance.

De Jongh was a member of the South African Association of Artists and exhibited extensively in South Africa and abroad during his lifetime, including his first exhibition in South Africa in 1922 and an exhibition in London in 1932. The Total Gallery in Johannesburg held a Memorial Exhibition in his honour in 1981. He fulfilled a number of public commissions for prominent South African buildings and a series of illustrations for the tuition of medical students at the University of Cape Town.

De Jongh is represented in the Stedelijk Museum and Rijksmuseum in Amsterdam, in most prominent public collections in South Africa, and extensively in private collections.