Despite the proposed ‘certainty’ in a city or region hosting a mega-event, there has long been issues of uncertainty surrounding the planning and implementation of what have until now essentially been mega-projects. Large events have found a variety of ways to adapt and respond to unforeseen circumstances due to political conflicts, planning of oversize venues, limited time of implementation, and legacies that are difficult to manage. Considering the further increased uncertainty surrounding the planning of mega-events as a result of the COVID-19 pandemic, this paper examines how an accompanying cultural component—e.g., the Cultural Olympiad—may help cities that plan for events like the Olympics transition toward diversified drivers and long-term legacy. In particular, the case of cultural offering in Milan between the two mega-events of Expo 2015 and the upcoming 2026 Milano-Cortina Olympic Games shows how host cities can address growing uncertainty through the expanded role of a cultural programme combined with the rescaling of traditional mega-event formats. With this purpose, 2012 London Cultural Olympiad has been selected as an antecedent example—with positive and negative outcomes—to critically review the relationships between the Olympics and the Cultural Olympiad, as well as their widespread spatial strategy and public engagement. In addition, the paper offers more general conclusions regarding learning potentials of jointly studying mega-events and cultural policy.