Teaching and learning are very essential in life. These skills should be well mastered. However, there are only a few people who know how to teach and learn well. The paper aims to describe the most important skill in the 21st teaching and learning. This paper is a narrative literature review. Literature was taken from Science Direct and Google Scholar. It is recommended to master creative thinking skills in the problem-solving method of teaching. This method is essential in learning and teaching. The teacher can learn to be more creative in explaining any subjects to the students in different ways. On the other side, the students can be trained how to think creatively by using the given theory. In this way, the students will not only memorize the subject but also practice creatively. This skill is long-lasting. It can be implemented in any subject, including English, medicine, arts, science, etc. Conclusion: The most important skill in the 21st teaching and learning is mastering creative thinking skills in the problem-solving method of teaching. This skill is essential for teachers and students. It is long-lasting.