Background: The issue of grandparents’ support provided to their families is undertaken in Polish literature very seldom. There are no studies concerning single mother families. The purpose of the article is to examine the extent to which grandparents provide support to grandchildren brought up in single mother families, and determine the relationship between the grandparents’ support and the grandchildren’s quality of life. Materials and Methods: The survey data were collected from 119 people from single mother families. The Student’s Life Satisfaction Scale SLSS was used to test the quality of life and the Social Support Scale (SWS) was used to test the strength and type of support from grandparents. Results: Mother’s parents are involved in each of the considered types of support in a higher degree than father’s parents, regardless of the place of residence of the single mother family. In small towns maternal grandparents provide information support more often than paternal grandparents, maternal grandmothers engage in instrumental aid to grandchildren more often than paternal grandparents. In cases of families living in large cities, when the paternal grandfather gives instrumental, emotional or evaluative support, grandchildren assess their quality of life significantly better. The assessment of quality of life is also higher in cases of maternal grandfather’s emotional engagement in support for grandchildren. Conclusions: The results suggest that the grandfathers’ (particularly paternal grandfather’s) support in the single mother family is positively connected with quality of life of grandchildren. It can be assumed that supporting grandparents contribute to strengthening the resilience of whole family.