They are among the rules outlined in new guidelines published by Fáilte Ireland.
Face coverings must be worn by guests when arriving to and lalso when the are leaving their table.
Only 50 people will be allowed in a function area, including staff, and sanitiser should be at each table.
Elaina Fitzgerald Kane, from the Irish Hotels Federation, says many weddings will still go ahead.
"I suppose what we are seeing now is couples are getting very creative and getting personalized masks. There are cleary trying to get in the spirit of things."
"We have hosted very successful and very enjoyable weddings and we still have couples who are anxious to go ahead and their date means something to them.
She said a lot of people are choosing to go down the route of a more intimate setting because of the guidelines.
Under the new restrictions indoor events were reduced from 50 people to just six people, except for businesses such as shops and restaurants.
The government made it clear that indoor weddings and some religious services, such as mass, are exempt from the new restrictions, meaning they can still take place with up to 50 people.
