This study explored motivation and engagement among North American (the United States and Canada; n = 1,540), U.K. (n = 1,558), Australian (n = 2,283), and Chinese (n = 3,753) secondary school students. Motivation and engagement were assessed via students' responses to the Motivation and Engagement Scale-High School (MES-HS). Confirmatory factor analysis using Mplus found good fit for each of the four samples. Multi-group invariance tests demonstrated comparable factor structure, reliability, distributional properties, and correlations with a set of validational factors across the four groups. Results hold implications for international assessment of motivation and engagement, research, and data analysis.