Abstract: Due to their unique physical and chemical properties, two-dimensional (2D) boron nanosheets have received tremendous research attention and demonstrated substantial value in electronic devices, biomedicine, and energy conversion. In the preparation of boron nanosheets, compared with the bottom-up synthesis predominantly employed for electronics, the top-down synthesis route offers more facile and scalable production. In this mini-review, we mainly discuss the recent advances in the synthesis of boron nanosheets using the top-down strategy and the relevant applications in energy catalysis. Finally, inspired by our recent works on the novel applications of 2D silicon, we put forward prospects for designing boron nanosheets, providing insights into developing viable techniques for high-performance heterogeneous catalysis.