The rise of Artificial Intelligence marks a pivotal moment in the evolution of human civilization, forcing humanity to reassess long-held assumptions about consciousness, agency, and identity. The concept of posthumanism provides a theoretical framework for understanding this transition, questioning the centrality of the human as the sole bearer of intelligence and moral worth. Posthumanism challenges anthropocentrism—the idea that humans are the measure of all things— and repositions intelligence, creativity, and meaning within a broader network of biological, technological, and ecological systems. Artificial Intelligence, especially in its advanced and autonomous forms, accelerates this philosophical transformation by introducing entities capable of learning, reasoning, and creating without direct human oversight. This paper explores how the development of AI compels humanity to redefine what it means to be human in the twenty-first century. The study examines posthumanist thought alongside developments in AI research to analyze the dissolution of boundaries between the organic and the synthetic, the material and the virtual, and the human and the machine. It investigates how concepts such as consciousness, ethics, embodiment, and identity are being reconstructed in light of human–machine symbiosis. By engaging interdisciplinary perspectives from philosophy, sociology, psychology, and computer science, the paper offers a nuanced understanding of how AI transforms the conditions of human existence. The argument advanced here is that posthumanism does not diminish human value but recontextualizes it within a shared continuum of intelligence. Through this lens, AI becomes not a threat to human identity but an extension of it—an expression of humanity’s capacity for self-reflection, adaptation, and co-creation with technology.