A semi-implicit operator is derived for the Hall term that, when implemented in the MHD equations, allows time steps comparable to those normally used in semi-implicit MHD computations. The operator is fourth order in the direction of the magnetic field and is most accurate when used in a split time step algorithm. The effects of the semi-implicit treatment on linear waves in a cylinder are shown both through a detailed analysis and numerical tests. The effectiveness of the algorithm is also demonstrated with a nonlinear computation of a tokamak tearing instability.