This article explores the concept of 'left-behind' places in the context of rising spatial inequalities and political discontent. The term refers to post-industrial and rural areas characterised by economic under-performance and decline. The special issue aims to develop a broader understanding of the diverse meanings and manifestations of 'left-behind' places. The editorial reviews how the term has been conceptualised in the literature and introduces the contributions according to four themes: the origins and meaning of the term 'left behind'; the production of 'left behind places' through socio-spatial restructuring; (re)conceptualising 'left behindness' in terms of feelings of embitterment and hope; and, unpacking how local and national actors respond to decline and marginalisation. The concept of 'left-behind' places has become widely used to refer to post-industrial cities and towns as well as some rural areas characterised by economic underperformance and decline. These places are held to have been 'left-behind' by broader processes of globalisation, technological change, labour market restructuring and political realignment. While the term 'left-behind' places is new, these underlying processes have been in operation since at least the 1970s, generating spatially uneven outcomes between growing and underperforming regions. The post-2008 concern with 'left-behind' places can be seen as somewhat Anglo-American in origin, with such regions often referred to by different labels in different countries. The special issue seeks to develop a broader understanding of the diverse meanings and manifestations of 'left-behind' places by exploring the origins and meaning of the term; examining their production through broader processes of socio-spatial restructuring; (re)conceptualising 'left-behindness' in terms of the contrasting feelings of embitterment and hope; and, unpacking how local and national actors respond to decline and marginalisation. The special issue provides a critical, cross-national examination of 'left-behind' places, seeking to go beyond the overarching label and the narratives of socio-spatial polarisation, decline and discontent that it evokes to bring out differentiated local conditions, experiences and practices, generating new insights and research directions.This article explores the concept of 'left-behind' places in the context of rising spatial inequalities and political discontent. The term refers to post-industrial and rural areas characterised by economic under-performance and decline. The special issue aims to develop a broader understanding of the diverse meanings and manifestations of 'left-behind' places. The editorial reviews how the term has been conceptualised in the literature and introduces the contributions according to four themes: the origins and meaning of the term 'left behind'; the production of 'left behind places' through socio-spatial restructuring; (re)conceptualising 'left behindness' in terms of feelings of embitterment and hope; and, unpacking how local and national actors respond to decline and marginalisation. The concept of 'left-behind' places has become widely used to refer to post-industrial cities and towns as well as some rural areas characterised by economic underperformance and decline. These places are held to have been 'left-behind' by broader processes of globalisation, technological change, labour market restructuring and political realignment. While the term 'left-behind' places is new, these underlying processes have been in operation since at least the 1970s, generating spatially uneven outcomes between growing and underperforming regions. The post-2008 concern with 'left-behind' places can be seen as somewhat Anglo-American in origin, with such regions often referred to by different labels in different countries. The special issue seeks to develop a broader understanding of the diverse meanings and manifestations of 'left-behind' places by exploring the origins and meaning of the term; examining their production through broader processes of socio-spatial restructuring; (re)conceptualising 'left-behindness' in terms of the contrasting feelings of embitterment and hope; and, unpacking how local and national actors respond to decline and marginalisation. The special issue provides a critical, cross-national examination of 'left-behind' places, seeking to go beyond the overarching label and the narratives of socio-spatial polarisation, decline and discontent that it evokes to bring out differentiated local conditions, experiences and practices, generating new insights and research directions.