This chapter introduces the concept of ‘unicorns’ as exceptionally successful privately held start-ups that have reached a valuation of US$1 billion, and succinctly describes the most prolific entrepreneurial ecosystems from emerging economies per number of unicorn ventures. Providing an overview of the transformational force of these high-impact ventures, unicorns are portrayed as symbols of extraordinary growth and innovation in the digital age, garnering substantial disruptive potential and attention from investors, media, politicians and the general public. The chapter highlights the importance of unicorns not only as economic powerhouses but also as sources of inspiration and impact for entrepreneurs, investors and the broader business community, through an exploration of the factors that have influenced their development in the emerging entrepreneurial ecosystems of the Global South. Our focus is on China, India, Southeast Asia, Eastern Europe and Russia, Latin America, MENA and Africa; subsequent chapters of this book analyse these regions in detail.