- County in northeastern Scotland until 1975, extending from the eastern Cairngorms to the North Sea and from near Fraserburgh to Aberdeen;
- A ceremonial area since then;
- A unitary authority from 1996, more extensive in area.
The county grew from a medieval sheriffdom based at Aberdeen, whose first recorded mention is in 1136 in the reign of David I . The sheriff acquired jurisdiction in the Earldoms of Mar (in the southwest of the county) and Buchan (in the north) and in the districts of Garioch and Strathbogie between them. Until the Local Government Act of 1889 there were several pockets of Banffshire within the county.
In 1929 the Scottish counties gained in powers at the expense of most of the burghs, but in Aberdeenshire, the city of Aberdeen became completely independent of the county administratively as it was already so far as the Lord Lieutenant was concerned, the Lord Provost acting as Lord Lieutenant within the city.
Aberdeenshire became part of the Grampian Region in 1975, and (including the city of Aberdeen) was divided among four of the districts. The county only survived ceremonially, with its Lord Lieutenant.
In 1996 a new unitary authority of Aberdeenshire united the three former Grampian districts of Banff & Buchan, Gordon, and Kincardine & Deeside. The new authority included former Aberdeenshire (without Aberdeen), pre-1975 Kincardineshire and northeastern Banffshire. Three Lord Lieutenants have duties within the area of the unitary authority: one for Aberdeenshire (the old county, excluding the city of Aberdeen), one for Kincardineshire (the southeast) and one for Banffshire (the northwestern corner of the authority, plus the northeast of neighbouring Moray).