Born in Amsterdam, Constant was a founding member of the experimental group CoBrA in 1948, which emphasized spontaneity and folk art influences. He later transitioned from painting and sculpture toward architectural theory and urban planning, seeking to redefine the relationship between humans and their environment.

His signature work, New Babylon, occupied him for nearly two decades, consisting of elaborate models, maps, and collages that envisioned a global network of interconnected, elevated structures. This project remains a seminal exploration of utopian urbanism and the potential for creative play in a technologically advanced society.

Constant's influence continues to be recognized in contemporary discourse regarding the intersection of technology and human identity. His work is frequently included in major institutional surveys, such as the 2026 New Humans: Memories of the Future exhibition at the New Museum, which examines the historical and future impacts of technological evolution on human life.