Mega sporting events (MSEs) such as the FIFA World Cup and the Olympics always attract people around the world to visit the hosting country, boosting its tourism and business, and leaving a positive legacy. However, such events also leave significant negative impacts on the environment such as an increase in greenhouse gas (GHG) emissions in the host and neighboring countries. Considerable research efforts have been devoted to reducing such negative impacts and maintaining the sustainability of infrastructure associated with MSEs. The infrastructure construction in the host country of an MSE is the main and inevitable source of GHG emissions. In particular, the construction work of stadiums. This study presents comprehensive research on scope-based carbon footprint analysis related to two phases, i.e., the construction phase and operation phase of stadiums, by taking the eight world cup stadiums in Qatar as a case study. A life cycle assessment is used to quantify the potential environmental impacts of these stadiums at different stages. The Ecoinvent database is used to quantify the emission factor at each phase. According to the findings, Scope 3 (indirect supply chain) emissions are greater than Scope 1 (direct on-site) emissions, and the construction supply chain is found to be a significant contributor to the carbon footprint of the stadiums, accounting for 98% of the total GHG emissions. The results also show that electricity, district cooling, and waste generation are the three top contributors of GHG emissions with 35%, 25%, and 21% emissions, respectively. Moreover, it is vital to implement innovative approaches such as circular design for end-of-life material recycling and reuse of structural components, which can support a transition toward sustainable and carbon-neutral mega events. Thus, this study presents the role of circular economy in achieving carbon-neutral FIFA World Cup Qatar 2022. This research will contribute to enhancing the future benefits of the sustainable construction of infrastructure projects for mega events and help in harmonizing mega event strategies with national circular economy targets.