The first element is the plural genitive case of hǫrðar, the name of an old Germanic tribe (see Charudes).

The flag is a banner of the coat of arms derived from the old seal of the guild of St. Olav from Onarheim in Tysnes municipality.

This seal was used by the delegates of Sunnhordland in 1344 on the document to install king Haakon V of Norway.

In the 7th century, the area was made up of many petty kingdoms under the Gulating and was known as Hordafylke from around the year 900.

The Bergenhus len was headquartered in Bergen and encompassed much of western and northern Norway.

In 1972, the neighbouring municipalities of Arna, Fana, Laksevåg and Åsane were annexed into the city of Bergen.

A county is also an election area, with popular votes taking place every 4 years.

The municipalities in Hordaland were divided among four district courts (tingrett): Nordhordland, Sunnhordland, Bergen, and Hardanger.

Hordaland was also part of the Gulating Court of Appeal district based in Bergen.

Gulen and Solund in Sogn og Fjordane county were also part of the Hordaland police district.

Bømlo, Etne, Fitjar, Stord and Sveio were a part of the "Haugaland and Sunnhordland" police district, along with eight other municipalities in Rogaland county.