Background: In addition to inequalities related to gender, age and socio-economic background, poor cognitive function may affect receipt of help and impair quality of life. We investigate whether people with dementia or low cognition with a disadvantaged background, experience more unmet need and/or more unrequired help than older people with similar levels of functional limitation, and associations with quality of life. Methods: We studied people aged 50+ in the English Longitudinal Study of Ageing. Cognitive status was divided into three groups: dementia (by physician diagnosis and/or proxy questionnaire, n=405); low cognition but no dementia (lowest quartile in the mean of z-scores of orientation, immediate recall and delayed recall, n=4,520); and intact cognition (n=10,264). Counts of unmet need (not receiving help for the need) and unrequired help (receipt of help without the respective need) were used as outcomes in two-part regressions. Quality of life (CASP-19) was a continuous outcome in a linear regression. Socio-demographic factors (gender, age, having partner/child and socioeconomic status), functional limitation, and their interaction with cognitive status were included in the models. Results: People with dementia or low cognition at lower levels of functional limitation had more unmet need and received more unrequired help. At higher levels of functional limitation, unmet needs were more frequent among the cognitively intact while unrequired help did not differ by cognitive status. Women, younger individuals, and those with a partner had fewer unmet needs but received more unrequired help, mostly among the cognitively intact. Higher socioeconomic status was associated with fewer unmet needs and unrequired help regardless of cognitive status. Both unmet need and unrequired help were associated with poorer quality of life independent of cognitive status. Conclusions: Unmet need may be a particular challenge in early dementia. Unrequired help that may decrease autonomy is a problem at all levels of cognition. Lower socioeconomic status undermines the receipt of sufficient help. Our results highlight the importance of a good-quality timely diagnosis of dementia, comprehensive and accurate needs assessment, and person-centred care planning to identify those with unmet need and receiving unrequired help in order to improve their quality of life.