According to the Marriage Act, there are three types of legal marriages in Ireland:

  1. Civil
  2. Secular
  3. Religious

Here are the 3 marriage types explained:

Civil Marriage Ceremony

The defintion of a civil marriage ceremony varies from country to country and this is where the confusion lies. In Australia for instance, a civil ceremony is a ceremony conducted according to the wishes and beliefs of the couple instead of the rules of a Religious body. But this is not the case in Ireland.

Here in Ireland a civil marriage ceremony must be strictly non-religious despite the beliefs and wishes of the couple. A civil marriage ceremony can only be conducted by Registered Marriage Solemniser who is registered as an employee of the HSE Civil Registration Office. This may be either a Civil Registrar or their Registry Office staff.

Secular Marriage Ceremony

A secular marriage ceremony can be conducted either by Registered Marriage Solemniser who is registered as a member of a Secular body, or a member of a Religious body which permits interfaith ceremonies for people from all faiths or none.

Religious Marriage Ceremony

A Religious marriage ceremony is conducted by a Registered Solemniser who is registered as a member of a Religious body with a spiritual purpose along with a belief in God. 

This includes interfaith Solemnisers, who are permitted to conduct legal marriage ceremonies of any style according to the beliefs and wishes of the couple, on any day of the week, at any time, at any place with a postal address.

A religious marriage ceremony may also be an interfaith ceremony, your most flexible choice for a non-Church legal marriage ceremony in Ireland.

Interfaith Ceremonies

An interfaith ceremony is your most flexible choice as it recognises all beliefs or none, and can combine and cross the boundaries of both Secular and Religious ceremonies. An interfaith ceremony can be either Secular, Spritual or Religious therefore providing you with the most options for the design of your ceremony.

So if you’d like a legal marriage ceremony but you don’t want a Registry Office marriage or to be married in a Church, your best choice for a Celebrant/Solemniser is to choose from a Religious body which permits interfaith ceremonies.

No wonder there is so much confusion online. But it makes perfect sense really. It all comes down to the type of ceremony being conducted.

Reference:

https://en.wikipedia.org/wiki/Secular_religion