In many Western countries, divorce among older age groups has slowly increased. One potential explanation is the increase in the diversity of family structures, such as a blend of joint children, stepchildren and stepgrandchildren. We investigate the association between multigenerational family complexity and late-life divorce in Sweden (60 +). Multigenerational family complexity includes a couple's joint children/grandchildren and any children/grandchildren to whom one of the partners is a parent/grandparent, i.e. when the female partner, male partner or both partners have children/grandchildren from previous unions. Using Swedish register data, we find that couples with step relationships are more likely to divorce than those with only biological ties, that couples with only joint children or grandchildren have the lowest late-life divorce risk, and that couples with two sets of stepchildren face a higher risk than those with one. We also find that joint children in stepfamilies lower divorce risk among couples where the female partner has children from previous unions and for couples with both joint and step grandchildren, regardless of the stepchild's parental lineage. Lineage patterns of family complexity in the third generation operate somewhat differently than those in the second generation do. We provide novel insights into how biological and stepties as well as maternal and paternal lineages across generations are related to divorce risk later in life.