Not, strictly speaking, a traditional song. The lyric was written by the poet James Hogg (1770-1835), and appears with music in typical collections of Scottish "national" song, usually with piano accompaniment and sometimes with the alternative spellings Athole or Athol. The melody is attributed to Niel Gow the Younger, grandson of the famous fiddler Niel Gow.

Here is an updated link to staff notation at Richard Robinson's Tunebook:

Cam' ye by Atholl