This study determines the numerical solution of linear mixed Volterra-Fredholm integral equations of the second kind using the linear spline function. The proposed method is based on using the unknown function’s linear spline function at an arbitrary point and converting the Volterra-Fredholm integral equation into a system of linear equations with regard to the unknown function using the integration method. By solving the given system, an approximate solution can be easily established. This is done with the help of a computer program that uses the Python code program version 3.9. Furthermore, we demonstrated theoretical results on the method’s uniqueness and convergence analyses.