Caregiving for older relatives is central for many people's lives in aging societies. The timing of caregiving onset significantly influences caregivers' health, social, and employment trajectories. However, the age at which family caregiving begins and its potential social and intersectional stratification have not been sufficiently explored. Using data from the Survey of Health, Ageing and Retirement in Europe (SHARE), we analysed individuals becoming daily caregivers between waves 1 and 9 (ages 50–95). We applied Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) to determine intersectional inequalities in the age of caregiving onset, separately for intragenerational (partner, siblings) and intergenerational (parents, in-laws) caregiving. We created 48 intersectional strata with combinations of sex/gender, migration background, education, and occupation. Intragenerational care onset was at 70.18 years on average (N = 10,146), with 11 years of difference between strata. Intersectional strata explained substantial variation in onset age (VPC = 7.14%), and 10% of these differences were due to intersectional interaction effects. Intergenerational care (N = 3,966) began earlier at 59.56 years on average, with a difference of over 4 years between strata. Most between-strata variation was additive. For both intra- and intergenerational care, combinations of women with low-skill occupations and high education were associated with earlier caregiving onset. We found large differences in the age of caregiving onset between intersectional strata in both intra- and intergenerational care. Mapping social heterogeneity and the intersectional nature of caregiving onset within the life-course is critical to further understand the prerequisites, meaning, and consequences for family caregivers.