  An overview of top physics and phenomenology at a high-energy linear collider
is presented. A comprehensive study of top quark physics is possible at such a
facility. The unique threshold production of top pairs would provide
measurements of fundamental properties, such as mass and total decay width, to
unmatched precision. Above threshold, the full set of Standard Model and
anomalous electroweak top couplings can be readily measured with excellent
precision. It should also be possible to measure the top Yukawa coupling. This
set of measurements would allow a definitive test of the widely held notion
that the top quark may play a special role in physics beyond the Standard
Model.
