Using TIMSS 2015 data, the present study aimed to explore the profiles of attitudes toward science among Hong Kong eighth-grade students (N = 4138), and further to investigate how these attitudinal profiles might relate with gender and science achievement. In TIMSS, attitudes toward science are specified in terms of four factors: intrinsic interest in science, perceived competence in science, instrumental value of science, and engaging science teaching. Results of a latent profile analysis indicated five distinct profiles of student attitudes toward science: (1) Negative attitudes, particularly toward perceived competence in science; (2) Negative attitudes, particularly toward instrumental value of science and engaging science teaching; (3) Moderate attitudes toward science; (4) Positive attitudes toward science; and (5) High-positive attitudes toward science. Furthermore, boys displayed significantly higher intrinsic interest in science, perceived competence in science and instrumental value of science than girls. Generally, students in profiles with higher levels of science attitudes tended to show better science achievement, but the relationship was not perfectly linear. The findings suggest ways for educators and parents to plan and implement effective and individualized strategies to foster student motivation in science learning.