Hi,
Thank you very much for your message.
Unfortunately, it may be difficult to find records without a more specific place of origin. Civil registration did not begin in Ireland until 1864 so prior to this marriages would have been recorded by the local parish church which is why you really need to know the name of the parish where the wedding took place to know where to look for the record.
There are some places online where you can look, hopefully you will be lucky and find some record of the family that will help establish parish of origin:
http://churchrecords.irishgenealogy.ie/churchrecords/ have begun a project to upload Irish church records to their site free of charge. However so far only Catholic records from Cork city and parts of the county have been uploaded so far.
www.familysearch.org has a huge database of genealogical records including some church records for Ireland.
www.rootsireland.ie have a large collection of Irish Church records, however you have to pay to use this site.
Kind regards,
Genealogy Support