This chapter examines the fashion industry’s systemic reliance on animals and the economic and ecological externalities it generates, including land degradation, pollution, exploitative labor, and opaque supply chains. It introduces “circumfauna,” a macroeconomic framework for understanding the global shift away from animal-derived inputs. Fashion, which is often dismissed as frivolous despite its $1.8 trillion scale, provides a revealing lens into how unregulated, animal-based production continues to shape material economies. Circumfaunal fashion, by contrast, aligns with emerging policy, investment, and supply chain shifts that prioritize circularity, biodiversity, and resilience. Drawing on economic case studies and current regulatory trends, the chapter outlines specific policy interventions such as subsidy reform, procurement incentives, and investment in circular infrastructure. Ultimately, circumfauna is positioned as both a framework and a market signal—a means to reimagine fashion’s global role while enabling more just and sustainable economies.