  The present lecture notes are an introduction to selected topics of {\it
Galactic Dynamics}. The focus is on topics that we consider more relevant to
the main theme of this workshop, {\it Celestial Mechanics}. This is not
intended to be a review article. In fact, any of the topics below could be the
subject of a separate review. Only the main ideas and notions are introduced,
as well as some important currently open problems in each topic. Some relevant
results from our own research are also presented. We discuss topics related
mostly to the so-called {\it ellipsoidal components} of galaxies. These are
\textbf{a)} the dark halos of both elliptical and disk galaxies, \textbf{b)}
the luminous matter in elliptical galaxies, and \textbf{c)} the bulges of disk
galaxies. We shall only occasionally refer to the dynamics of disks, bars or
spiral structure.
