What is the cheapest ferry to Ireland from Scotland?

If you are looking purely at the lowest starting fare, Cairnryan to Larne with P&O Ferries currently tends to come out cheaper than Cairnryan to Belfast with Stena Line. When I checked on 17 August 2026, the Direct Ferries route pages were showing Cairnryan–Larne from £28 and Cairnryan–Belfast from £36. Those are lead-in prices, not fares you are guaranteed to get for your dates. If you are also booking the journey home, check the current Stena Line Voucher Codes: the Bf20 voucher code currently gives 20% off ferry trips from Ireland to Scotland, so it may reduce the Belfast-to-Cairnryan return leg.

There is one important distinction. The direct ferries from Scotland sail to Northern Ireland, not directly to Dublin or another port in the Republic of Ireland. From Cairnryan, P&O sails to Larne and Stena Line sails to Belfast. If you are continuing south, the cheapest ferry ticket is only one part of the cost.

Cairnryan to Larne or Belfast: which ferry is actually cheaper?

The current price evidence points towards Larne, but not by enough to treat it as a universal rule. The Direct Ferries Cairnryan–Larne page was showing fares from £28 when I checked, while its Cairnryan–Belfast page started at £36.

The same source's route data gives a useful second comparison because it separates different traveller types. Its figures, last updated on 1 August 2026, put the average foot-passenger price at £109 for Larne and £115 for Belfast. The average price with a car was £382 for Larne and £388 for Belfast. Again, Larne was slightly lower, but only by £6 in both examples.

• Cairnryan to Larne: P&O Ferries, around 2 hours, Direct Ferries lead-in fare from £28.
• Cairnryan to Belfast: Stena Line, around 2 hours 15 minutes, Direct Ferries lead-in fare from £36.
• Recent average foot-passenger prices: £109 to Larne versus £115 to Belfast.
• Recent average prices with a car: £382 to Larne versus £388 to Belfast.

P&O also has the shorter crossing. Its Cairnryan to Larne route takes about two hours, while Stena gives around 2 hours 15 minutes for Cairnryan to Belfast.

I would use these figures as evidence that Larne is a sensible first route to price, not as proof that P&O will always be cheaper. Ferry fares move with dates, sailing times, passenger numbers, vehicles and available promotions.

A family, foot passenger and motorhome can get different answers

A single cheapest-ferry answer becomes less useful once you change the booking. Both routes accept foot passengers and vehicles, but current promotions can alter the result.

Families should compare the offers on both routes rather than assuming one operator has the advantage. P&O currently has a Kids Go Free offer for qualifying Cairnryan–Larne bookings, while Stena is also running Kids Go Free on eligible Cairnryan–Belfast motorist fares. Both are scheduled for travel up to 5 January 2027, subject to their separate booking terms.

Students have a similar reason to compare rather than choosing on headline fare alone. Stena's Students Go Free promotion applies to qualifying student passengers travelling in a car with an adult or senior citizen, and P&O is currently advertising its own Students Go Free Irish Sea offer.

For motorhomes, P&O has a more route-specific saving: its midweek motorhome offer prices an eligible motorhome at the car rate on Tuesday, Wednesday and Thursday sailings in 2026, subject to the stated restrictions.

The practical point is simple: compare the final fare for the people and vehicle you are actually taking. A promotion that removes a child or student fare can matter more than a small difference between the two basic route prices.

Driving to Dublin? The cheaper ferry fare can lose some of its advantage

If Dublin is your real destination, arriving in Larne leaves you further away than arriving in Belfast. The road-distance figures I checked put Belfast to Dublin at roughly 106 miles and Larne to Dublin at roughly 128 miles, a difference of about 22 miles.

That difference is not enormous, but it is large enough to put a small ferry saving into context. As an illustration, a petrol car averaging 40mpg would use about 2.5 litres of fuel over an extra 22 miles. Using the RAC-reported UK average petrol price of about 161.5p per litre in mid-August 2026, that is roughly £4 of extra fuel. The real figure for your car could be higher or lower.

The mileage figures are route-planning estimates rather than a promise of the exact distance you will drive, and fuel prices are volatile. The RAC Fuel Watch updates UK pump-price information regularly, so use the current figure if you are doing the calculation later.

In other words, if Larne is only £5 cheaper for your booking and you are driving straight to Dublin, most of the ticket saving could disappear in the extra road journey. If it is £30 or £50 cheaper, Larne may still leave you comfortably ahead.

I would compare the routes using the ferry fare after any applicable discount, then add the onward journey from Belfast or Larne to where you are actually staying.

Where you are going in Ireland can change the best route

Belfast and Larne are close enough for the ferry choice to look interchangeable, but your destination changes the calculation.

If Belfast itself is your destination, the Stena crossing has an obvious location advantage. Larne can make more sense for Larne itself, parts of County Antrim and journeys around the Antrim Coast. For Dublin and destinations further south, Belfast starts you further down the island, so the gap between the two ferry fares matters more than the headline percentage saving.

For Donegal or a longer touring holiday, check both routes against the actual place you are heading next. I would not switch arrival port simply to save £5 or £10 without checking whether the extra mileage and time erase the difference.

When are Scotland to Ireland ferry fares cheapest?

There is no single cheapest day or month that I could verify for every booking. The more useful approach is to compare nearby travel dates and sailing times.

Stena's Low Fare Calendar is useful if your dates can move. Stena says midweek departures can sometimes cost less than weekends and that some late-night sailings can be cheaper than daytime crossings. Its fare guidance also says a £10 booking fee applies to telephone or in-person Travel Centre bookings, which is another reason to compare the online total before paying.

Direct Ferries can also be useful when you want to see route prices and departure times in one search rather than opening the two operators separately. If you decide to book through it, check the current Direct Ferries voucher codes before payment in case a relevant saving is available. I would still compare the final payable price with booking directly, rather than assuming either route is automatically cheaper.

Check the return crossing separately before you decide

A return trip does not have to produce the same price comparison in both directions. This matters when a promotion only applies one way.

My Favourite Voucher Codes currently lists Bf20, giving 20% off ferry trips from Ireland to Scotland. You can check its current terms on our Stena Line voucher codes page.

I would not use that saving to claim Stena is cheaper for the outward Cairnryan-to-Belfast journey because that is not what the offer says. Instead, price Scotland-to-Ireland normally, then check whether Bf20 reduces the Belfast-to-Cairnryan journey home. That can change the return-trip total even if P&O has the lower starting fare on the outward crossing.

P&O has its own route-specific offers to compare. Its current Cairnryan–Larne deals include Kids Go Free, student travel offers, midweek motorhome and caravan promotions and a 25% discount on qualifying returns lasting up to 28 hours. Those offers have different eligibility and travel conditions, so compare only the ones that fit the trip you were already planning.

Why published “from” prices do not always match

One thing became clear while I was checking the routes: ferry price pages can show more than one perfectly legitimate figure at the same time. On Direct Ferries, for example, the Cairnryan–Larne route page showed a £28 overall starting price while its foot-passenger section showed fares from £25. The Belfast page showed £36 as its route starting price, while other booking results can surface different fares for particular dates or passenger types.

That is why I would not compare a foot-passenger lead-in fare with a car-and-driver price and conclude that one operator is dramatically more expensive. For a useful comparison, keep the passengers, vehicle, dates and fare type as close as possible.

The recent Direct Ferries averages are helpful here because the same source uses the same type of route data for both crossings: £109 versus £115 for foot passengers and £382 versus £388 with a car. They support the idea that Larne has recently been slightly cheaper without pretending that the £6 gap will appear on every booking.

If your plans may change, compare the fare conditions as well

The cheapest ticket upfront can become poor value if changing it later costs more than the saving.

Stena describes Economy as its lowest and most restrictive fare. Changing the route, date or departure time can mean an amendment fee plus any fare difference, and an Economy cancellation does not receive a refund. Flexi allows online changes without an amendment fee, although any increase in the new fare still has to be paid. Its published cancellation terms are also more flexible.

That does not mean Flexi is automatically the better buy. If your travel plans are fixed, Economy may still leave you paying less. If dates are uncertain, compare the price difference with what a later amendment or cancellation could cost.

Which crossing should you price first?

• Lowest starting fare: price Cairnryan–Larne first; the current comparison evidence tends to favour P&O.
• Going to Belfast: price Stena first because it takes you directly to your destination.
• Driving to Dublin: compare both after allowing for roughly 22 extra road miles from Larne.
• Travelling with children or students: check both operators' current eligibility offers before deciding.
• Taking a motorhome: include P&O's current midweek motorhome promotion in the comparison if your dates qualify.
• Booking a short return: check whether P&O's 28-hour return offer fits the trip.
• Returning from Ireland to Scotland: check whether the current Stena Bf20 offer reduces your return leg.
• Dates may change: compare flexible fares as well as the cheapest Economy price.

For most people looking for the lowest headline fare, Cairnryan to Larne is the route I would price first. But the gap in recent comparison data is small enough that Belfast should still be checked, particularly if it shortens your onward drive or a promotion matches your passengers. The useful answer is not which operator has the smallest advertised number; it is which route leaves your whole journey costing less.

Frequently asked questions

Written by Julian House 17th August 2026