The speed of sound has been measured in heavy water,D2O, by a pulse technique. An equation is presented to express the results of these measurements in analytic form and is used to compute tables of sound speed inD2O. A comparison of the sound speeds inD2Oat atmospheric pressure obtained by an optical method, an interferometer method, and the present pulse method is made. The results from the pulse method and the optical method agree within the experimental error; however, the interferometer method gave higher sound speeds than the other two.