Croatia - Passport & Nationality - Croatian Citizenship - Grandparent born in Croatia
Croatian emigrants and their direct descendants (e.g. children and grandchildren) may apply for Croatian citizenship in some circumstances. The key requirement is that a grandparent was born in Croatia. The language and culture tests are no longer required, and the relevant parent(s) or grandparent(s) do not need to still be alive.
There are exceptions. If your parent or grandparent left Croatia before October 8, 1991 and moved to another country within Yugoslavia, then their descendants cannot apply for Croatian nationality. If your grandparent left Croatia after October 8, 1991, then their descendants cannot apply for nationality either.
Croatia is a member of the European Union. As a result, a Croatian passport holder can live and work in any of the EU member states (including Ireland).