Older adults with chronic illness, as well as their primary caregivers in multigenerational families, may experience a complex interplay of factors that affect their quality of life (QOL). However, this interplay is not yet well-characterized for Chinese multigenerational families in particular. In this study, we analyzed how family resilience and social support affect the QOL of both older adults and caregivers in multigenerational Chinese families specifically. We enrolled 258 pairs of older adults with chronic illness and their primary caregivers in a multicenter cross-sectional study conducted in southern China in December 2021. Using the Actor-Partner Interdependence Model (APIM), we then examined the correlation between family resilience, social support, and QOL in dyadic analysis and found that QOL, family resilience, and social support for primary caregivers were better than those of older adults with chronic illness ( = 3.66-16.3, ＜0.01). These factors were found to be positively correlated ( = 0.22-0.60, ＜0.05), except for the family resilience of primary caregivers and the QOL of older adults with chronic illness ( = -0.14,  = 0.04). Additionally, actor effect results showed that when a dyadic member has high family resilience and objective social support, they tend to have a better QOL ( = 0.5-1.48 < 0.01). However, partner effect results showed that when the primary caregiver has high family resilience, this is associated with a worse QOL for the older adult ( = -1.06,  < 0.01). Furthermore, we found that objective social support of dyads does not significantly influence their partner's QOL ( = 0.88/0.31, ＞0.05) for any pair. This suggests that medical staff should pay attention to the impact of family resilience on the QOL of older adult and caregiver dyads and explore health management plans that focus on binary coping in multigenerational families.