Background: Although there is an increasing recognition of the importance of critical thinking in science education across the world, the relevant research literature is extremely thin. There is an urgent need to generate more empirical evidence. Purpose: We examined two essential issues concerning critical thinking (the relationship between students' and teachers' critical thinking as well as the relationship between critical thinking and science achievement) in the context of physics education. Sample: We utilized data from the 2017 (Chinese) Program for Regional Assessment of Basic Education Quality with 46,820 students under 547 teachers from 128 schools. Design and methods: We developed multiple membership multilevel models to account for students from different schools and under multiple teachers (in each school). Results: After control over student, teacher, and school characteristics, although Chinese eighth graders demonstrated statistically significant critical thinking, there was not any statistically significant relationship between students' and teachers' critical thinking. With the same control, there was a statistically significant relationship between students' critical thinking and students' physics achievement among Chinese eighth graders. Meanwhile, there was not any statistically significant relationship between teachers' critical thinking and students' physics achievement (over and above the relationship between students' critical thinking and students' physics achievement). Conclusion: We suggest that critical thinking may need to become an essential and explicit outcome of science education to help establish a relationship between students' and teachers' critical thinking and promote the correlation between critical thinking of students and teachers and students' science achievement.