By Plane

The Republic of Ireland has three major international airports. They are, in order of size, Dublin (DUB) (www.dublinairport.com; 1/814-1111), Cork (ORK) (www.cork-airport.com; 021/431-3131), and Shannon (www.shannonairport.com; 061/712000). Northern Ireland’s main airport is Belfast International Airport (BFS) (www.belfastairport.com; 028/9448-4848).

The Republic of Ireland has several smaller regional airports. The airports at Donegal and Kerry offer service to Dublin; in addition, the airports at Donegal, Kerry, and Knock receive some (limited) European traffic. In Northern Ireland, the secondary airports are Belfast City Airport and Derry City Airport. Airline service to these smaller airports changes frequently, so be sure to consult your preferred airline or travel agent as soon as you begin to sketch out your itinerary.

Begin thinking about flying plans at least 6 months ahead of time. Consider exchange-rate movements: Fares may be calculated in U.S. dollars, British pounds, or euros, depending on the airline. The key window for finding a deal is usually between 5 and 6 months ahead of your departure according to a study of some 21 million fare transactions by the Airline Reporting Corporation (a middleman between travel agencies and the airlines). They also found that those who booked on a Sunday statistically found the best rates (on average paying 19% less than those who booked midweek).

The glory days of generous frequent flyer programs and bucket loads of free miles are no more, but those who collect miles via credit cards (rather than trying to fly to get them) are having better luck getting free trips nowadays. The key strategy is to get a card that will work with a number of airlines, rather than one branded by a particular airline (the latter usually have less generous rates of return and more draconian fees). The forum Flyertalk.com is a handy resource for learning how to get the most out of your miles (both for airlines and hotels); such companies as AwardMagic.com and IFlyWithMiles.com can help stressed travelers redeem miles for flights for a flat fee that’s usually far less than a ticket from the United States to Ireland would have cost.

Run searches through the regular online agents such as Expedia, as well as metasearch engines like DoHop.com, Kayak.com, and Skyscanner.net. For complex journeys, with multiple departures, doing multiple searches (so that affordable intra-European airlines such as Ryanair, Flybe, and EasyJet show up on the search) is a good way to find deals; a specialist flight agent such as RoundtheWorldFlights.com or AirTreks.com will also likely save you money.

By Ferry

If you’re traveling to Ireland from Britain or the Continent, traveling by ferry is a good alternative to flying. Several car and passenger ferries offer reasonably comfortable furnishings, cabin berths (for longer crossings), restaurants, duty-free shopping, and lounges. You may be surprised, however, by how long it takes, even from super-near neighbor Britain; the quickest U.K.–to–Ireland ferry route is Holyhead to Dublin, which is a little over 3 hours; the sailing from Fishguard to Dublin takes well over 7 hours. From Cherbourg in France it's a whopping 18 hours. 

Prices fluctuate seasonally and depend on your route, time of travel, and whether you are on foot or in a car. Check with your travel agent for up-to-date details, but the lowest one-way adult fare in high season on the Holyhead to Dublin ferry starts at £30. A car usually costs about £80 including one adult passenger, plus £30 per extra adult, £15 extra child.

Irish Ferries (www.irishferries.ie; 0818/300-400 in the Republic of Ireland, or 353/818-300-400 in Northern Ireland/U.K.) operates between Pembroke, Wales, and Rosslare, County Wexford. It also sails from Cherbourg and Rosscoff in France.

Stena Line (www.stenaline.com; 01/204-7777) sails from Fishguard, Wales, to Rosslare; and from Cairnryan, Scotland, and Liverpool, England, to Belfast, Northern Ireland.

P&O Irish Sea Ferries (www.poferries.com; 0871/664-2121 in Britain, 01/407-3434 in Ireland, or 352/3420-808-294 in the rest of the world) operates from Liverpool to Dublin and from Cairnryan, Scotland, to Larne, County Antrim, Northern Ireland. 

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.