English from the 16th century. From the Greek male name Dorotheus, meaning "gift of God". National variants are shown under Dorothea [q.v.].
[Note: this has a similar meaning to the male names Dieudonne, Matthew, Nathaniel and Theodore.]
In Scotland Dorothy is the Anglicized form of the Gaelic Diobhail/Diobhall. As these may also be Anglicized as Devorgilla, this name and Dorothy are classified here as Lesser Synonyms.
The 1841 Census of Aberdeenshire has a few spelling variations which should all be found using Soundex searching. Dorothea was used in old documents in Latin. Search on Doroth* to take account of Latin case endings.
Whyte suggests that Diorean [Scottish Gaelic equivalent of Doreen] could be an Irish rendition of Dorothy.