A general introduction to conformal maps and the Riemann mapping theorem is given. Three methods for numerically approximating conformal maps from arbitrary domains to the unit disc are presented: the Schwarz-Christoffel method, the geodesic algorithm and the circle packing method. Basic implementations of the geodesic algorithm and the circle packing method were made, and program code is presented. Applications of these numerical methods to problems in physics and mathematical research are briefly discussed.