In this paper, Haar wavelet collocation method is applied to obtain the numerical solution of a particular class of delay differential equations. The method is applied to linear and nonlinear delay differential equations as well as systems involving these delay differential equations. In addition to this the method is also extended to numerical solution of delay partial differential equations with delay in time. The method is applied to several benchmark test problems. The numerical results are compared with the exact solutions and the performance of the method is demonstrated by calculating the maximum absolute errors and experimental rates of convergence using different numbers of collocation points. The numerical results show that the method is simply applicable, accurate, efficient and robust.