The social inclusion of people with dementia (PwD) is recognised as a global goal of legislation, societal initiatives and service provision. Ensuring the social inclusion of PwD in these areas implies that its dimensions and domains are clear and unambiguous. However, the concept of social inclusion as it is currently used by researchers and practitioners is often vague or acts as a container concept for a variety of different approaches. This paper reports on an integrative review that analysed qualitative and quantitative studies on social inclusion and exclusion of PwD. It focused not only on the empirical results of the included studies but also on the theoretical embedding and methodological approaches to the concept of social inclusion and exclusion. We find that empirical studies on the social inclusion of PwD are scarce and largely characterised by a lack of or inconsistent conceptualisation. Against this background, the operationalisation of the concept and the assessment of the individual aspects of social inclusion with standardised instruments seem to be premature. Substantial theoretical and methodological work is needed to guide research on the social inclusion of PwD. The empirical results show that relationships with other people and being integrated into social networks are essential aspects of social inclusion. Likewise, the strategies and attitudes of caring persons can help to create or reinforce exclusion.