Economies are increasingly more globalized and digitalized than ever before. This signaled and challenged the current education systems to alter and train future employees for a more dynamic, complex, and fast-paced 21st-century workforce. The main purpose of this review paper is to highlight existing studies on key soft skill competencies of 21st-century known as the “4 Cs” critical thinking, collaboration, creativity, and communication among school students and to explore various frameworks about 4 Cs in the current literature. This review paper also provides suggestions for future research in this area.