This paper presents the results of a literature review focusing on the use and potential of Fermi problems (FPs) in the STEM disciplines. We identify different usages and roles given to FPs in each of the STEM disciplines and highlight their potential to promote modeling of real phenomena and situations as well as learning about the estimation of quantities. Modeling is found to be at the heart of integrating the different STEM disciplines and estimation is a key facilitator that enables students to tackle complex situations and content in all disciplines. The results of the review are discussed in terms of the potential and possibilities of FPs to support the development of twenty-first century competencies in the STEM disciplines.