Dictionary of Family Names

GALBRAITH.   A compound of two Gaelic words, Gall and Bhreatan, that is, strange Briton, or Low Country Briton.  The Galbraiths in the Gaelic are called Breatannich, or Clanna-Breatannich, that is, the Britons, or the children of the Britons, and were once reckoned a great name in Scotland, according to the following lines:—

"Bhreatanuich o'n Talla dhearg,
Hailse sir Alba do shloinneadh."

"Galbraith's from the Red Tower,
Noblest of Scottish surnames."

The "Talla dhearg," or "Red Tower," was probably Dumbarton, that is, Dun Bhreatain, the hill or stronghold of the Britons, whence it is said the Galbraiths came.  Galbraith, Welsh, the diversified plain.