The latest top quark mass measurements by the CDF and D0
experiments are presented here.  The mass has been determined in the
dilepton (tt-bar --> e mu, ee, mu mu + jets + missing E(t)) and lepton plus
jets (tt-bar --> e or mu + jets + missing E(t)) final states.  The most
accurate single result from lepton plus jets channel is
173.5+3.7_-3.6(stat. + Jet Energy Scale Systematic +/- 1.3(syst.)  GeV/c2,
which is better than the combined CDF and D0 Run I average.  A preliminary
and unofficial average of the best experimental Run II results gives M_top =
172.7 +/- 3.5 GeV/c2.