This chapter introduces and explores the two fundamental Taoist systems theories (the Yin–Yang and the Five Elements), its core principles (oneness/wholeness, paradox and interdependence) and dynamics (balancing cycles of generation and control, self-regulation and harmonization). This explanation is framed against two central aspects that make the theories applicable today. On the one hand, it identifies the type of Yin–Yang creative tensions that work as harmonizing opposites as a way to raise awareness and better manage systems challenges. On the other hand, it illustrates how these two theories are utility-focused. They are useful sustainable management tools for navigating amid increasing complexity in the mindsets, behaviours and agency of entrepreneurs, executives, managers and organizations. Utility is illustrated with real case examples and metaphors.