Frederick Drach Tappert (April 21, 1940 – January 9, 2002) was an American physicist whose primary contributions were in underwater acoustics. He is noted for the development of the parabolic equation model and split-step Fourier algorithm for electromagnetic and ocean acoustic propagation. Tappert began his scientific career in the field of plasma physics, receiving his Ph.D. from Princeton University in 1967. His dissertation, entitled "Kinetic theory of equilibrium plasmas", was supervised by Edward A. Frieman, then Associate Director of the Princeton Plasma Physics Laboratory.