Black's Surnames of
Scotland merely lists the name Moffat as being of local origin from the
town of Moffat in Dumfriesshire.
However, the Scottish Clan
& Family Encyclopedia claims that the name Moffat is of Norse origin and
that the family gave their name to the town not the other way round. The
entry goes on to say that the ancestor of the Moffats - William de Mont Alto
- married the youngest daughter of Andlaw who came from Norway during the
tenth century. The name softened over time from de Mont Alto, through
Montealt, to Movat and finally to Moffat.