This study aims to explore how the interplay between desire and agency is portrayed in The Flowers of Evil (1857) through the perspective of posthumanism and psychoanalysis. This study is qualitative and follows an exploratory and explanatory research approach, with a primary focus on generating insights and ideas to better define a research problem that has not been previously examined. Desire is the basis of analytic experience for psychoanalysts such as Sigmund Freud, Jacques Lacan, Carl Jung, and Melanie Klein. Lacan expands upon the Freudian concept of desire which has been linked to the effort toward independent movement and the contrast between what is found and what is sought: negativity and lack that drive the indestructible pursuit of desire. Unconscious desire is then the core of existence that drives actions, giving people agency in their desire. Posthumanists like Karen Barad, Bruno Latour, Rosi Braidotti, and Jane Bennett take the question of agency as a crucial aspect to showcase the capacity of ‘I’ to think and intervene for humans and non-humans wherein the capacity to fulfil desires through actions lies. Since objet petit a is that lost shard of the subject’s being that can only be regained through satisfying the desire of the Other, it can extend agentic capacities to nonhuman and even non-animate actants by distributing agency across a wide range of entities, structures, and processes in “Benediction” (the sun, the wind, the clouds), “The Albatross” (the sea, the sky, the deck), “A Carcass” (the carcass, the worms), and “To the Reader” (poison, daggers, arson). In conclusion, the interplay between desire and agency creates a porous and relational system that is based not on subjects or objects but on assemblages of humans and non-humans.