A lack of well-trained clinical oncologists can result in significant cancer health disparities. The magnitude of this problem around the world is poorly described in the literature. A comprehensive global survey of the clinical oncology workforce was conducted. Data on the number of clinical oncologists in 93 countries were obtained from 30 references. The mortality-to-incidence ratio was estimated by using data on incidence and mortality rates from the GLOBOCAN 2012 database; the ratio was > 70% in 26 countries (28%), which included 21 countries in Africa (66%) and five countries in Asia (26%). Eight countries had no clinical oncologist available to provide care for patients with cancer. In 22 countries (24%), a clinical oncologist would provide care for < 150 patients with a new diagnosis of cancer. In 39 countries (42%), a clinical oncologist would provide care for > 500 patients with cancer. In 27 countries (29%), a clinical oncologist would provide care for > 1,000 incident cancers, of which 25 were in Africa, two were in Asia, and none were in Europe or the Americas. The economic and social development status of a country correlates closely with the burden of cancer and the shortage of human resources. Addressing the shortage of clinical oncologists in regions with a critical need will help these countries meet the sustainable development goals for noncommunicable diseases by 2030.