Social exclusion has a negative impact on quality of life. People living with dementia or mental health disorders as well as informal carers have been separately described as socially excluded. The objective of this systematic narrative review was to examine the extent to which social exclusion experienced by adult informal carers of people living with dementia or severe mental health disorders has been identified and described in research literature. It synthesised qualitative and quantitative evidence and included the perspectives of carers themselves and of professionals.