Background: Population aging places greater demands on the supply of informal carers. The aims of this study were to examine (1) the types of unmet support needs of carers of older Australians and (2) the association of unmet needs with mental health.; Methods: Utilizing new data from the 2015 Australian Bureau of Statistics (ABS) Survey of Disability, Ageing and Carers, we calculated the prevalence of carers experiencing specific and multiple unmet needs for support, using single and multiple item measures.