1. The Old Parish Registers (OPRs) record births/baptisms, marriages, and burials before the introduction of compulsory registration on 1st January 1855. These registers were compiled by parish ministers on a voluntary basis. There are numerous gaps in these registers. It should be noted that in most Orkney parishes burials were not recorded.
Microfilms of the original OPRs are available in the Orkney Archives, in Edinburgh at New Register House and the Scottish Genealogical Society, in London at the Society of Genealogists, and as microfiches or CD-ROM at LDS Family History Centers worldwide.
The GRO(S) index to births/baptisms and marriages in the OPRs is available online at the Scotland's People website. This is a fee-based service, even for searching the indexes, but very convenient. You need a credit card in order to register. Once you have located the records you want it is also possible to order complete extracts of those records online.
The Church of the Latter Day Saints (LDS) produces an index to the births/baptisms and marriages listed in the OPRs. It is known as the IGI (International Genealogical Index) and is available on microfiche at many public libraries and at LDS Family History Centres worldwide. Hard-copy print-outs can be purchased at some LDS centres. The IGI includes all the OPR births/baptisms and marriages for Orkney parishes. It can be accessed online free of charge. Most LDS centres also have microfiche copies of the indexes to civil registrations of births and marriages for the period 1855-1875 and for the year 1881. It should be noted that
The IGI contains some pre-1855 material and some post-1855 material resulting from private research.
many entries in the OPRs contain home addresses and the names of witnesses at baptisms and marriages but that such details are not carried forward to the IGI.
the spelling of a surname could vary from time to time and from parish to parish.
both GRO(S) and IGI indexes are subject to copying errors.
Walt Custer has on his website copies of IGI pages covering a great many Orkney family surnames. A very useful resource.
Mike Bostwick has put the records of 16,796 Orkney marriages and baptisms on his website.
2. Minutes and other records of Synods, Presbyteries, and Kirk Sessions of the Established Church of Scotland and the Free and Secession Churches.
Details vary from parish to parish. Kirk Session minutes include references to adulterers and illegitimate conceptions. Many include lists of communicants and of the poor. Some include registers of mortcloth dues and burials additional to those listed in the OPRs.
These records are held by the Orkney Archives. Microfilm copies of most are available at the National Records of Scotland, Edinburgh.
A very useful website belonging to Meg Greenwood displays material of genealogical interest taken from the records of Free Church congregations in some Orkney parishes. At present only the parishes of Orphir and Stenness are covered.
3. Minutes and other records of the General Assembly of the Church of Scotland and of the Catholic, Episcopal and other churches.
These are held by the National Records of Scotland, Edinburgh.