  Top quarks can be produced abundantly at hadron colliders like the Tevatron
at Fermilab and the Large Hadron Collider at CERN, and a variety of
measurements of top-quark properties have been gathered in the recent years
from four experiments: CDF and D0 at the Tevatron and ATLAS and CMS at the
Large Hadron Collider. In this review the most recent results on the
measurement of the top-quark mass by the four different collaborations, with
various techniques and considering different topologies, are reported.
