Who painted the first abstract picture?

There is no single answer, because "first" depends on what you call abstract. Abstract art uses shape, form, colour and line to make a composition that can exist with a degree of independence from the visible world, and abstraction runs along a continuum, from slight departures from reality to total abstraction with no trace of anything recognisable. Draw the line early and you get one winner, draw it later and you get another.

The most striking early claim belongs to Hilma af Klint, a Swedish artist who painted her first abstract series in 1906, at the age of 44. A considerable body of her work predates the first purely abstract compositions by Kandinsky, Malevich and Mondrian. She belonged to The Five, a circle of women inspired by Theosophy who tried to contact the High Masters through séances, and she wrote that the pictures were painted directly through her, without preliminary drawings. She felt the world was not ready for them and asked that they stay unseen until twenty years after her death.

Wassily Kandinsky is generally credited as one of the pioneers of abstraction, and his case is built differently: he promoted it in his treatise On the Spiritual in Art and thought music was the model, since music does not represent the exterior world but expresses inner feelings immediately. In 1912 Kupka showed an abstract painting, and in 1915 Malevich completed his first entirely abstract work, Black Square. Every one of them can be called first, on a different definition.