Gregory Bateson observed that cybernetics is not essentially about "exchanging information across lines of discipline, but in discovering patterns common to many disciplines". This paper adopts his line of thought to join the dots between cybernetics and the philosophy of Existentialism, and then interconnect both with contemporary art. It demonstrates that while terminologies may differ, many of the three fields' primary concerns closely cohere. The world's most ground-breaking artists are found to apply and fuse cybernetic paradigms and Existentialist themes, from Robert Rauschenberg and Marina Abramović to Damien Hirst, Stelarc and Anish Kapoor. The research offers the first detailed comparison between cybernetics and Existentialism, and reveals surprising commonalities. Feedback loops, circular causality and negative entropy are not only central tenets of cybernetics, but also of Existentialism. Autonomy, autopoiesis and interactivity equally unite both fields, and each is visionary and forward looking in seeking radical change and transformations. Both explored artistic endeavours, with Existentialists Jean-Paul Sartre and Albert Camus equally renowned for their powerful novels and plays as their philosophical works, while cybernetic art became a major phenomenon in the 1960s following the landmark exhibition <em>Cybernetic Serendipity: the Computer in the Arts</em> (1968), and influenced artistic practices thereafter.