Guy Cassiers (1960) initially studied graphic art at the Academy of Fine Arts in Antwerp. Though his interest turned to theater during that period, his training as a visual artist has always played a crucial role in his development as a theater maker. Cassiers continues to view the theater as an outsider and it is from that position that he created an artistic idiom that is all his own. In terms of the content of his work, this outsider position translates as a preference for solitary, isolated and often asocial figures. In terms of form, it translates as a preference for literary texts (as opposed to dramatic texts) and the use of visual technology. He adapted and staged novels by well known authors such as Marcel Proust, Robert Musil, Virginia Woolf, Joseph Conrad, Lev Tolstoj, Yusunari Kawabata and Marguerite Duras.

He was the artistic director of OHS, a youth theater in Ghent (1987-1992), of the Ro Theater in Rotterdam (1999-2006) and of Toneelhuis in Antwerpen (2006-2022). During this last period his growing interest in European history and in political themes like migration and terrorism resulted in such noted productions as Mephisto forever (Klaus Mann / Tom Lanoye), The Kindly Ones (Jonathan Littell), Borderline (Elfride Jelinek) Monsieur Linh and His Child (Philippe Claudel) and Les Démons (Dostojewski). Theater critic Pol Arias described Mephisto forever as the highlight of 2006: "Director Guy Cassiers does a magnificent job portraying that complex piece. Using discreet cameras, he lays emphasis, enlarges faces and portrays the fear, desperation or simply the vanity. The extremely subtle set refers to the Bourla theater itself, the lighting plays an important role as does the ingenious soundtrack. Equal praise goes to the actors who are all equally good. Together they stage a political play, one that is looking not to instruct but to question and they do that through their own world, that of the theater."

Guy Cassiers likes working in other languages. He recreated Monsieur Linh and His Child in an English, Spanish and Catalonian version. His distinctive, extremely visual theatrical idiom has made him one of the most highly regarded theater makers in Europe. Together with his actors, he creates a sensory universe in which music plays an increasingly important role. This has led to his interest in opera. He staged work The Ring des Nibelungen (Wagner), The Indian Queen (Purcell), Xerse (Cavalli) and modern operas by Kris Defoort, Rob Zuidam and Luca Francesconi.

Guy Cassiers won the Thersites Prize of the Flemish critics for his oeuvre as a whole (1997), the Amsterdam Prize for the Arts and the Werk-preis Spielzeiteuropa awarded by the Berliner Festspiele for his Proust cycle (2004), the Euro-pean Theatre Prize for New Theatrical Realities (2009) and, together with Ivo Van Hove, an honorary doctorate for services to society awarded by the University of Antwerp. In May 2017, Guy Cassiers received the insignia of Officer of the Order of Arts and Letters from the French Minister of Culture.

For Le Fresnoy Guy Cassiers wants to work on an installation that will visualize the ambiguity of the Overture of Mozart's Don Giovanni. The Overture to Don Giovanni is solemn and fore-boding: it is the music that underscores the Commandant's death; the music will reappear in the finale of the opera when the Comman-dant, now a stone Statue, arrives to dine with Don Giovanni. Musically, an andante emerges from the key of D minor, and then develops into a brilliant allegro in D major. The Overture music establishes the opera's subtle balance between comedy and tragedy, and also suggests that justice is in pursuit of Don Giovanni, the mercurial seducer. In an installation Guy Cassiers will try to translate this musical tension between comedy and tragedy, between vital lightness and coming doom in a visual and dynamic installation.