Objective <p>This systematic review aimed to identify the components of family support interventions implemented for family caregivers of women with breast cancer and to determine the most important components within each intervention<i>.</i></p> Methods <p>This systematic review, conducted according to the 2024 JBI evidence synthesis guidelines (PROSPERO Registration No. CRD42024509611), involved a comprehensive search of three databases—Scopus, PubMed, and Web of Science—to identify family support interventions for family caregivers of women with breast cancer up to January 2024. The methodological quality of the studies was assessed via the revised 2023 JBI critical appraisal tool for randomized controlled trials (RCTs). The findings were synthesized narratively.</p> Results <p>A total of 7,210 articles were identified, from which 31 full-text articles were reviewed. Ultimately, 15 articles were selected for data extraction. These studies involved 1,942 family caregivers of women with breast cancer. In the majority of studies, interventions were delivered individually. The number of supportive sessions ranged from 2 to 9. The most common mode of support delivery was in-person sessions. Social support (reported in 14 studies) was the most frequently provided type of support. Physical support was the least frequently reported, appearing in only 2 studies.</p> Conclusion <p>This review compiled and integrated a list of various components of supportive interventions for family caregivers of women with breast cancer. The findings highlight a greater focus on social, emotional, and informational dimensions in the design of interventions. These findings underscore the need for greater emphasis on these underrepresented dimensions in the design of future supportive interventions for family caregivers of women with breast cancer.</p>