Friedensreich Hundertwasser (1928–2000) was an Austrian painter, architect, and sculptor best known for his architecture characterized by colorful, ornamental, and biomorphic shapes. He initially gained acclaim for his paintings, but later became more renowned for his unique architectural styling.

Inspired by the Vienna Secession movement, especially the work of Austrian painters Egon Schiele and Gustav Klimt, Hundertwasser incorporated his decorative, labyrinthine spirals into his paintings, architecture and designs for postage stamps and flags. He developed his own theory of “transautomatism”, which was inspired by the Surrealist concept of automatism (painting or drawing without conscious self-censorship), and sought to loosen the rigid rules of conventional art to emphasize the viewer’s experience. Hundertwasser's architectural style is often compared with those of Antoni Gaudi.

In the 1950s, Hundertwasser began designing architectural projects. These designs use irregular forms, and incorporate natural features of the landscape. The Hundertwasserhaus apartment block in Vienna is one famous example. This building has undulating floors, a roof covered with earth and grass, and large trees growing from inside the rooms, with limbs extending from windows. He took no payment for the design of Hundertwasserhaus, declaring that the investment was worth it to "prevent something ugly from going up in its place".