The purpose of science education is scientific literacy, which is extended in its meaning in the 21st century. Students must be equipped with the skills necessary to solve problems from the community beyond obtaining the knowledge from curiosity, which is called ‘computational thinking’. In this paper, the authors tried to define computational thinking in science education from the view of scientific literacy in the 21st century; (1) computational thinking is an explicit skill shown in the two steps of abstracting the problems and automating solutions, (2) computational thinking consists of concrete components and practices which are observable and measurable, (3) computational thinking is a catalyst for STEAM (Science, Technology, Engineering, Arts, and Mathematics) education, and (4) computational thinking is a cognitive process to be learned. More implication about the necessity of including computational thinking and its emphasis in implementing in science teaching and learning for the envisioned scientific literacy is added.