A key trend in the development of the global economy is the informalisation of employment. A number of studies have emerged that capture the growth and characteristics of non‐standard employment in Japan and South Korea as two major world economies that are experiencing relative decline in growth. However, limited is understood in the role of institutional actors in shaping the labour markets and how these two neighbouring countries may, despite similarities, differ in terms of forms of non‐standard employment and the institutional and cultural reasons that underpin the differences. This review study fills part of the gap by providing a systematic analysis of changes in the labour market in Japan and South Korea, the role of institutional actors in shaping the informal labour market, patterns of non‐standard employment and its impacts on individual workers as well as the development of the labour market. The paper concludes that informalisation has led to the decline of job quality on a relatively large scale in these two countries and that a greater level of state intervention is necessary to maintain workforce well‐being and economic sustainability.