Yes, you can absolutely cruise from Southampton to Greece, though it is a lengthy and luxurious voyage. In 2026, lines like Cunard, P&O Cruises, and Princess Cruises offer Mediterranean itineraries that depart from the UK. These cruises typically last between 14 and 21 nights round-trip. Because of the distance, the ship must sail south through the Bay of Biscay, past the coast of Portugal, and through the Strait of Gibraltar before reaching the Greek Isles. You will often have several "sea days" at the start and end of the trip, with stops in Spanish or Italian ports along the way. For travelers who prefer not to fly, these "No-Fly" cruises are highly popular in 2026, offering a grand tour of Europe that culminates in iconic stops like Santorini, Mykonos, or Athens (Piraeus). Prices generally start around £1,800 to £2,500 per person for a standard cabin.