This book contains the lecture notes for the course on ”Soil Dynamics”, as given at the Delft University of Technology until the year 2002. The book has been updated continuously since 1994, and the material may be further adapted and expanded in the future. The book mainly presents theoretical solutions of soil dynamics problems, with emphasis on the full derivation of all solutions, using integral transform methods. These methods are presented briefly in an Appendix. The elastostatic solutions of many problems are also given, as an introduction to the elastodynamic solutions, and as a possible limiting state of the corresponding dynamic problems. For a number of problems of elastodynamics of a half space exact solutions are given, in closed form, using methods developed by Pekeris and De Hoop. Also some approximations are presented in which the horizontal displacements are disregarded, an approximation suggested by Westergaard. This is the version of the book in PDF format, which can be downloaded from the author’s website <geo.verruijt.net>. It can be read using the ADOBE ACROBAT reader. The text has been prepared using the LATEX version (Lamport, 1994) of the program TEX (Knuth, 1986). The PICTEXmacros (Wichura, 1987) and the macro wrapfigure have been used to prepare the figures. The program is distributed together with some computer programs to illustrate the solutions. Many comments of colleagues and students on the material in this book have been implemented in later versions, and errors have been corrected. All remaining errors are the author’s responsibility, of course. Further comments, for instance by e-mail to the author’s address, will be greatly appreciated.