This chapter introduces associated matrices of graphs, providing a powerful framework for analyzing graphs using linear algebra. We explore incidence matrices, circuit matrices, and cut-set matrices, which capture the relationships among vertices, lines, and cut-sets. Additionally, we consider certain polynomials associated with graphs through determinants of matrices. Throughout this chapter, the underlying field \(\mathbb {K}\) is either \(\mathbb {R}\) of real numbers or \(\mathbb {C}\) of complex numbers.