Whether grandparental investment is associated with the development and well‐being of grandchildren has been investigated in several studies. Those studies have considered grandparental investment in three types of family circumstances: the investment of non‐coresiding grandparents, grandparental presence in three‐generational households, and custodial grandparent families where children are raised without parental presence. The investment of non‐coresiding grandparents has been found to be associated with improved child well‐being in the majority of studies. In contrast, children living in custodial grandparent families often achieve worse outcomes compared to other children. Finally, findings regarding child well‐being in three‐generational households have provided mixed results. This entry reviews the prior studies, discusses their limitations, and provides themes for future research.