Ranked by gross tonnage, the industry's standard size measure — Royal Caribbean builds nine of the sixteen largest ships afloat.
Pictured: Royal Caribbean’s Icon of the Seas, #1 at 248,663 gross tons.
| Rank | Ship | Gross tonnage | Cruise line |
|---|---|---|---|
| 1 | Icon of the Seas (2024) | 248,663 GT | Royal Caribbean |
| 2 | Star of the Seas (2025) | 248,663 GT | Royal Caribbean |
| 3 | Legend of the Seas (2026) | 248,663 GT | Royal Caribbean |
| 4 | Utopia of the Seas (2024) | 236,473 GT | Royal Caribbean |
| 5 | Wonder of the Seas (2022) | 235,600 GT | Royal Caribbean |
| 6 | Symphony of the Seas (2018) | 228,081 GT | Royal Caribbean |
| 7 | Harmony of the Seas (2016) | 226,963 GT | Royal Caribbean |
| 8 | Oasis of the Seas (2009) | 226,838 GT | Royal Caribbean |
| 9 | Allure of the Seas (2010) | 225,282 GT | Royal Caribbean |
| 10 | MSC World America (2025) | 216,638 GT | MSC |
| 11 | MSC World Europa (2022) | 215,863 GT | MSC |
| 12 | Costa Smeralda (2019) | 185,010 GT | Costa |
| 13 | Carnival Celebration (2022) | 185,010 GT | Carnival |
| 14 | Arvia (2022) | 184,700 GT | P&O |
| 15 | Iona (2020) | 184,089 GT | P&O |
| 16 | AIDAnova (2018) | 183,858 GT | AIDA |
No matching rows.
The first Icon-class ship, debuting in January 2024 as the largest cruise ship ever built. Its headline feature is Category 6, the largest waterpark at sea, with six water slides across seven decks — plus a capacity of up to 7,600 passengers at full occupancy.[1]
Icon of the Seas' sister ship, named in August 2025 and sailing year-round from Port Canaveral, Florida. Built to the identical Icon-class specification, it ties for the title of the world's largest cruise ship rather than surpassing it.[2]
The third and newest Icon-class ship, debuting in summer 2026. Like its two sisters it shares the same gross tonnage, so the "world's largest" title is currently a three-way tie decided by launch order rather than size.[3]
An Oasis-class ship built specifically for short getaways — 3-night weekend and 4-night weekday sailings out of Florida — rather than the week-plus itineraries most mega-ships run, packing a full-size cruise ship's worth of attractions into a much shorter trip. It was built at the Chantiers de l'Atlantique shipyard in France and christened in July 2024 by singer Meghan Trainor, and it's also the first Oasis-class ship powered by liquefied natural gas.[4]
Held the title of world's largest cruise ship from its 2022 debut until Icon of the Seas launched in 2024. It's the fifth and final ship of the Oasis class, the design family that first broke the 200,000-gross-ton barrier back in 2009.[5]
The fourth Oasis-class ship, Symphony of the Seas held the title of world's largest cruise ship for nearly six years after its 2018 debut — the longest reign of any ship on this list — before Icon of the Seas finally surpassed it in 2024. At its November 2018 christening in Miami, it made cruise-industry history by naming actors Alexa and Carlos PenaVega and their toddler son as its "godfamily" rather than a single godmother, the first time a family had sponsored a ship.[1]
The third Oasis-class ship, Harmony of the Seas introduced attractions like a zip line and the FlowRider surf simulator when it launched in 2016, features that became a template for the even larger ships Royal Caribbean built afterward. Its own headline attraction, the Ultimate Abyss slide, drops riders 10 decks and about 150 feet in roughly 13 seconds, making it one of the tallest slides at sea when it opened.[1]
The ship that started the Oasis class in 2009, Oasis of the Seas was the first cruise ship ever to break the 200,000-gross-ton mark, a leap in scale so large that several ports had to adapt their terminals just to accommodate it. It was built at the same Turku, Finland shipyard that would later build the Icon-class ships, and its naming ceremony that year was unusual for having seven godmothers, one for each of the ship's themed neighborhoods, including singer Gloria Estefan.[1]
The second Oasis-class ship, Allure of the Seas launched in 2010 as a near-twin of Oasis of the Seas, sharing the same overall layout and most of the same onboard attractions, with only minor design refinements made after its sister ship's first year in service. Its godmother wasn't a real person at all: Shrek's Princess Fiona, rendered in 3D animation, became the first fictional character to christen a cruise ship at the ship's 2010 naming ceremony.[1]
The newest addition to MSC Cruises' World Class, MSC World America debuted in 2025 as the line's largest ship yet and its first vessel homeported full-time in the United States, sailing year-round from PortMiami. Like its sister ship MSC World Europa, it was built at the Chantiers de l'Atlantique shipyard in France, and actress Drew Barrymore served as its godmother at its April 2025 christening in Miami.[3]