Indoor air quality (IAQ) is a pressing yet globally underregulated public health issue, with growing scientific evidence linking poor IAQ to a wide array of health problems, including respiratory illnesses, cardiovascular disease, cognitive impairments, and increased risk of infection. Given that people spend most of their time indoors, addressing IAQ has become a critical area for policy intervention. This chapter examines the regulatory landscape governing IAQ, distinguishing between voluntary standards, non-binding guidelines, and enforceable legislation. It analyses the strengths and limitations of each regulatory tool and argues for a strategic, integrated approach to IAQ governance. Drawing on comparative case studies from the United States, Belgium, the United Arab Emirates, South Korea, and Taiwan, the chapter identifies promising innovations, including real-time monitoring, public labelling schemes, and building certification systems, as well as highlighting gaps in enforcement, public awareness, and regulatory coverage. The chapter also explores how IAQ regulation can be strengthened by embedding standards within existing legal frameworks, such as work health and safety laws and building codes. Emphasising the need for cross-sectoral collaboration and adaptive regulatory design, the chapter concludes by advocating for resilient, inclusive, and evidence-informed approaches to IAQ regulation that prioritise public health, environmental justice, and long-term sustainability.