Gavin Jantjes (born 1948) is a South African painter.
A native of Cape Town, Jantjes studied at the University of Cape Town's Michaelis School of Fine Art and the Hochschule für bildende Künste Hamburg, where he received a master's degree in 1972.
Jantjes was a founding member of the German anti-apartheid movement, he served for a time as consultant to the United Nations High Commissioner for Refugees. He settled in London in 1982, where he curated a number of exhibitions and lectured a great deal. He served on the advisory board of the Tate Liverpool from 1992 until 1995, and was a trustee of London's Serpentine Gallery from 1995 until 1998. From 1986 until 1990 he was a member of the Arts Council of Great Britain, and served as its consultant for the creation of the Institute of New International Visual Art (INIVA). For this group he coordinated a symposium on "New Internationalism". INIVA also published his book, A Fruitful Incoherence: Dialogues with Artists on Internationalism.
Jantjes became artistic director of Oslo's Henie-Onstad Kunstsenter in 1998, and he currently lives in the Norwegian capital.