International students may have less understanding and awareness of mental health issues and appear unlikely to seek help. The purpose of the current study was to construct and evaluate a brief online educational intervention designed to increase mental health literacy (MHL) and help-seeking among international tertiary students studying in Australia. The intervention was tested among 45 international tertiary students (undergraduate and postgraduate), who were randomly allocated to control and intervention conditions. The intervention led to significant improvements in help-seeking attitudes, particularly in stigmatising attitudes. No significant effects were found for MHL or help-seeking intentions. A brief educational intervention can improve help-seeking attitudes among international tertiary students. Future research may focus on establishing optimal intervention dosage.