Background: Nonprofit organizations (NPOs) in oncology are vital for patient advocacy and funding research for rare cancers, young investigators, and innovative projects. However, some cancers may be underfunded relative to their burden. This study examined the alignment of cancer burden by histology with NPO funding for each histology. Patients and Methods: This nationwide, cross-sectional study conducted from October 2017 through February 2018 included all oncology NPOs with >$5 million in annual revenue. Total revenue from NPOs supporting individual cancer types with the incidence, mortality, and person-years of life lost (PYLL) for each cancer type was compared using scatter plots and Pearson correlation coefficients. Correlation of expenditure types (eg, fundraising, patient education) with revenue was assessed using Pearson correlation coefficients. Effect of disease association with a stigmatized behavior (eg, lung cancer and smoking) was evaluated using descriptive statistics. Results: A total of 119 cancer-related NPOs were included, generating approximately $6 billion in annual revenue in 2015. Cancers with the largest revenue were breast cancer ($460 million; 33.2%), leukemia ($201 million; 14.5%), pediatric cancers ($177 million; 12.8%), and lymphoma ($145 million; 10.5%). Breast cancer, leukemia, lymphoma, and pediatric cancers were all well funded compared with their incidence, mortality, and PYLL. Gastrointestinal (colorectal, pancreas, and hepatobiliary), gynecologic (ovarian, cervical, and endometrial), brain, and lung cancers were poorly funded in all 3 metrics. All cancers associated with a stigmatized behavior were poorly funded in at least 2 metrics. Increased spending on fundraising, administrative costs, patient education, and treatment was highly correlated with increased revenue (Pearson correlation coefficients all >0.92). Conclusions: NPO funding by cancer type is not proportionate with individual cancer burden on society. Disease stigma negatively impacts funding. A significant need exists to increase awareness and funding for many undersupported but common and highly lethal cancers.