Globally, surveys have identified that medical learners of all levels perceive their oncology instruction to be inadequate. To address these gaps, we systematically developed and implemented the Oncology National Course for Advocacy, Research, and Education (ONCARE), a novel, nationally organized virtual course available to all Canadian medical students and evaluated its impact on oncology competency and interest. ONCARE was designed utilizing Kern's Six-Step Model for Curriculum Development. Components of ONCARE included lectures, career panels, and a mentorship program. Pre-course and post-course survey responses were collected to determine course impact on oncology knowledge and interest. Between October 2023 and March 2024, ONCARE enrolled 235 students representing 14 Canadian medical schools. One hundred forty (60%) students enrolled reported having only 0 to 10h of formal oncology instruction. Baseline interest in a career in oncology was high (mean Likert score 3.9/5) and remained unchanged following course completion. ONCARE increased both self-perceived knowledge in clinical oncology (mean Likert score 3.9/5 vs 2.9/5, p < 0.001) and confidence in oncology communication skills (mean Likert score 3.6/5 vs 3.1/5, p < 0.001). Ninety-seven percent of students were satisfied with the course (mean Likert score 4.6/5). The implementation of ONCARE as a proof-of-concept initiative builds upon previous educational interventions in oncology and highlights important principles for the development of related initiatives. Future work will target greater interdisciplinary and multinational collaboration as well as long-term follow-up of the ONCARE cohort.