Coinciding with a trend of rising economic divides within many countries, scholarly interest in the subject of inequality has grown significantly in the 21st century. Since its creation in 1987, the Social Inequality module of the International Social Survey Programme (ISSP) has evolved into an exceptionally comprehensive country-comparative individual-level database on public beliefs about inequality and socioeconomic conditions. The module stands out among international surveys due to its extensive thematic depth and breadth, along with the long times pan it covers. This provides unique opportunities for charting and monitoring longitudinal trends in social inequality, as well as for conducting comparative analyses aimed at advancing theories that incorporate the national context as an integral part of the explanatory framework. This introduction describes the content, coverage, and history of the fifth wave of the Social Inequality module (2019). This survey wave was conducted in 34 countries and combines previously fielded topics with new ones that speak to current debates in different areas of inequality research. The fifth wave introduces new questions focusing on anger and unfairness, reducing inequality by market actors, government inefficacy, lived experience of inequality, economic insecurity and deprivation, and social trust. This introduction chapter also presents some descriptive findings on these new topics, and offers an outlook on the content of this edited volume, which further explores these themes through a range of studies utilising the ISSP data.