Yes, travel insurance is mandatory to apply for an Ireland Visit Visa. Your insurance should cover medical costs, accidents, and emergencies in Ireland, with at least €30,000 coverage. It needs to last for your whole trip, including the days you travel. When you apply, immigration might ask for proof you have this insurance, and they could ask again when you get to the border. Also, travel insurance can protect you if something unexpected happens, like if you have to cancel your trip or need medical help.