Direct measurement of the top quark mass

We review the direct measurements of the top quark mass M-t using the sampl e of t (t) over bar events collected by the D (O) over bar and CDF experime nts at Fermilab. Measurements using events in the lepton plus jets, dilepto n, and all-hadronic t (t) over bar decay modes are reviewed, as is the comb ination of the results to yield the current world average M-t = 174.3 +/- 3 .2 (stat.) +/- 4.0 (syst.) GeV/c(2). We close by estimating the precision a ttainable with future data sets at Fermilab and the Large Hadron Collider.