BACKGROUND:The objective of this study was to describe young adult cancer caregivers' exposure to cancer misinformation on social media. METHODS: Eligible participants were 18 to 39 years old, used social media weekly, and cared for an adult patient with cancer diagnosed 6 months to 5 years before (N = 21). Recruitment occurred from August 2017 to June 2018 in person at oncology clinics and online. Semistructured telephone interviews were recorded and analyzed with grounded theory methods through 2 rounds of coding (κ = 0.88). RESULTS: Caregivers were on average 29.1 years old, female (76.2%), non-Hispanic White (90.5%), college educated (57.1%), and caring for a spouse/partner (47.6%). Caregivers were exposed to a variety of cancer misinformation topics; some felt uncertain in their caregiving ability when confronted with cancer misinformation. Caregivers crosschecked online sources and consulted trusted individuals (eg, family, friends, and health care providers) to determine the quality of cancer-related information and manage cancer misinformation. CONCLUSIONS: Cancer misinformation on social media may influence caregiving behaviors and decision making. Whether caregivers correctly and consistently identify cancer misinformation on social media is unknown. Supporting digital literacy to mitigate cancer misinformation on social media may improve young cancer caregivers' access to credible cancer information.