Malaysia has a nationwide COVID-19 vaccination programme to curb the COVID-19 pandemic. Medical students must help provide information about COVID-19 vaccination to the public. This study assessed the knowledge, attitude, and hesitancy towards COVID-19 vaccination among medical students. An online-based study was conducted involving 156 medical students at a private university. Sociodemographic characteristics, knowledge, attitude, and vaccination hesitancy were collected. Our research findings highlighted that insufficient knowledge and negative attitude may lead to COVID-19 vaccine hesitancy/refusal. 25% of our study population who were COVID-19 vaccine hesitant/refusal demonstrated insufficient knowledge (69.2%) and negative attitude (64.1%) towards COVID-19 vaccination. Nevertheless, 75% of the students have registered for COVID-19 vaccination, and most of them have good knowledge (59.8%) and showed positive attitude (58.1%) towards COVID-19 vaccination. Vaccination educational programmes focused on improving knowledge and cultivating positive attitude, should be conducted to maximise vaccine acceptance among medical students.