At a very early age he manifested an interest in music, mathematics and drawing and in adolescence began to publish caricatures in newspapers and magazines. After two years of study at the Civil Engineering School of the National Technical School (1897-1899) and having taken drawing lessons from Nikephoros Lytras (1899), he settled in Paris in 1900, where he remained for most of his life, travelling now and then to various countries and on occasion returning to Greece. Until 1902 he studied at the School of Fine Arts in Paris under Fernand Cormon, while from 1901 to 1912 he worked on many well-known humor magazines such as Frou-Frou, Le Rire, Le Sourire, and L’Assiette au Beurre publishing caricatures and drawings.
His systematic interest in engraving must have first expressed itself during a trip to Germany (1907-1909) and in 1918 he began to illustrate books, an activity which covered an important part of his creative activity and includes more than one hundred books, albums, diaries and art books. In 1930 he stopped painting and devoted himself almost exclusively to engraving. Having acquired French nationality, he taught at the Andre Lhote Academy (1925- 1928), gave lessons at his studio to Greek artists who were studying in Paris (1930-1937), and taught at the School of Fine Arts (1945-1952). In 1945 he was elected a member of the French Academy and in 1950 a corresponding member of the Athens Academy.
Exceptionally active in the exhibition world, both in France and other countries, his first solo show was held in Paris in 1922, and Andre Malraux wrote the preface to the catalogue. He also took part in Parisian Salons, while from 1920 to 1926 he held joint exhibitions with many of the most important artists of the period, such as Picasso, Matisse, Braque, Chagall and his close friend, Derain. In 1991 his work was presented in a retrospective exhibition at the Museum of Modern Art – Vasilis and Eliza Goulandris Foundation on Andros.
Dimitris Galanis was one of the most important engravers of the first half of the 20th century in Europe and the forerunner of modern Greek engraving, influencing his fellow artists both through his work and his teaching. Exceptionally skilled in all the techniques, he was the revitalizer of traditional methods of engraving. His work, which includes a variety of subjects — mythological and idyllic scenes, landscapes, nudes and still lifes – reveals influences from Cezanne in the beginning and the cubist and Fauvist movements, while later he acquired his own personal style, based on the principles of the classical tradition.