Background: There is increasing recognition of authorship inequity in academic medicine specialty publications. Analyses in other specialties note that female authors consistently comprise a minority of the first authors and an even smaller percentage of last authors. While this trend may be improving, we hypothesize that significant authorship gender disparities still exist in global oncology journals. Methods: This study comprehensively analyzes the gender distribution of authors for articles published in the Journal of Clinical Oncology Global Oncology (JCO GO), a premier journal in the field, from its inauguration in 2016 to March 2020. A total of 608 articles were identified as matching one of the following six article types: original report, editorial, commentary, case report, special article, and review article. We collected data such as the author’s position, gender, institutional affiliation, and country affiliation. Author gender was categorized as male, female, or indeterminate based on first name probabilities assessed by genderize.io, with a threshold probability of 0.8 based on prior studies. Authorship distribution was analyzed by region and country income level according to the World Bank classification. Results: Of the 608 article first authors, 47.5% were identified as male, while 41.4% were female. Male authors made up a comparatively higher proportion of the 592 last authors; 57.1% were identified as male compared to 32.1% who were female. A similar trend was seen among the 4102 middle authors; 51.4% were identified as male and 38.1% were female. The percentage of authors deemed indeterminate in the cohort was less than 11%. Female authors were more underrepresented among authors from low-income countries; they made up 21.6% of first authors and 9.1% of last authors. Authorship gender by world regions is summarized in Table below. Conclusions: Our analysis shows that authorship inequities persist in global oncology publications. Female authors from lower-income countries, and regions in Sub-Saharan Africa and South Asia, were markedly underrepresented. The underlying reasons for underrepresentation of female authors are multifactorial; further studies are needed to elucidate these factors and to develop and evaluate mitigating strategies.