<p>UK medical schools currently have no formal educational curricula for surgery and oncology. Many students and resident doctors also report low confidence levels and struggle to grasp key concepts within these fields. This study assessed the impact of an online teaching series on learner confidence in surgical oncology. Nine sessions focused on the surgical management of multiple forms of cancer were delivered. Learner confidence before and after the sessions was compared using paired t-tests, and qualitative feedback was collected and analysed using grounded theory. 275 people attended the sessions live from countries in Europe, Asia, and Africa, and 193 provided feedback. Attendees’ cumulative confidence rating was significantly higher after the sessions (<i>p</i> = 0.0001, t = 14.0, Cohen’s d = 4.06). 168 learners provided positive qualitative feedback, and 88 gave constructive criticism. Common strong points included the presentation, content, and visual materials used during the teaching. Recordings of the sessions were accessed by 391 learners across five continents. 48 provided feedback, and their mean confidence level was significantly greater after accessing the content compared to before (<i>p</i> = 0.0001, t = 8.104, Cohen’s d = 3.90). There are currently few formal teaching programmes focusing on surgical oncology. Our series successfully improved learner confidence about the surgical management of a variety of malignancies. The promotion of similar online teaching methods with improved interactivity and accessibility should allow more learners across the world to build confidence in this field.</p>