Théo Kerg (2 June 1909 – 4 March 1993) was a Luxembourgian painter and sculptor who specialized in modern art.
Kerg was born to a schoolmaster and his wife in Niederkorn, in south-western Luxembourg, Théo Kerg attended school in Esch-sur-Alzette. He moved to Paris, France, in 1929 to study at the École nationale supérieure des Beaux-Arts, the Sorbonne and the Institut d'art et d'archéologie. From 1932 to 1933, he studied at the Kunstakademie in Düsseldorf, Germany, under the supervision of Paul Klee and Oskar Moll. He returned to Luxembourg in 1936 to become an art professor.
In 1943, following the German invasion of Luxembourg in World War II, Théo Kerg resigned from his position. He was however subsequently arrested in 1944 by the Luxembourgian allied militia, and kept in prison for 15 months as a preventive measure. He left Luxembourg in 1946, aiming to settle in Venezuela, but stopped in Paris where he illustrated a book by Paul Eluard. He permanently settled in Paris, and spent the last three years of his life in Chissey-en-Morvan, in Burgundy, where he died in 1993.
Théo Kerg took part in over 300 group exhibitions and over 150 individual exhibitions. He founded a movement he called "tactilism", whereby a work of art would appear differently depending on the lighting, the atmosphere and other environmental variables.
In Luxembourg, he is remembered especially for his stained-glass windows at the Church of the Holy Spirit in Cents (1975).