Royal Caribbean doesn't just have the biggest cruise ship in the world. In Cruise Frog's ship data, it has the nine biggest.
We sorted all 604 ships listed as in service in our catalog by gross tonnage, the standard measure of a ship's enclosed volume. The top of the list is a Royal Caribbean wall, and you have to go to No. 10 to find another line.
All rankings and figures below come from Cruise Frog's own ship records. Cruise lines sometimes quote slightly different tonnage figures for the same ship, so treat close calls as close.
The top 10 largest cruise ships in service
| Rank | Ship | Debut | Gross tons |
|---|---|---|---|
| 1 (tie) | Icon of the Seas | 2024 | 248,663 |
| 1 (tie) | Star of the Seas | 2025 | 248,663 |
| 1 (tie) | Legend of the Seas | 2026 | 248,663 |
| 4 | Utopia of the Seas | 2024 | 236,473 |
| 5 | Wonder of the Seas | 2022 | 235,600 |
| 6 | Symphony of the Seas | 2018 | 228,081 |
| 7 | Harmony of the Seas | 2016 | 226,963 |
| 8 | Oasis of the Seas | 2009 | 226,838 |
| 9 | Allure of the Seas | 2010 | 226,637 |
| 10 | MSC World America (MSC) | 2025 | 216,638 |
All nine ships above MSC World America belong to Royal Caribbean.
Royal Caribbean's two classes own the top nine
The top three are the Icon-class sisters: Icon of the Seas, Star of the Seas and the newest, Legend of the Seas. Our records list all three at the same tonnage.
Spots four through nine belong to Royal Caribbean's six Oasis-class ships. The oldest, Oasis of the Seas, debuted in 2009 and is still bigger than any ship from another line.
Biggest is not the same as most crowded
The ship with the most guests in our top 10 is not a Royal Caribbean ship. MSC World America is listed at 6,762 guests, more than any Icon-class ship, on about 32,000 fewer gross tons.
That is why we also track the passenger space ratio, or gross tons per guest. A higher number means more room per person. In our data, Icon of the Seas scores 44.3, while MSC World America scores 32. For a ranking built on that measure, see our list of the most spacious cruise ships.
The next five
Just outside the top 10, our data shows:
- MSC World Europa (MSC Cruises), 215,863 gross tons
- Disney Adventure (Disney Cruise Line), 208,108 gross tons
- Costa Toscana (Costa Cruises), 186,364 gross tons
- Arvia (P&O Cruises), 185,581 gross tons
- Costa Smeralda (Costa Cruises), 185,010 gross tons
Disney Adventure stands out here. It is the biggest ship in our data from a line other than Royal Caribbean or MSC.
Bigger ships are on the way
The list will keep changing. Our catalog shows several large ships due in the next few years, including:
- MSC World Asia, due in December 2026
- Hero of the Seas, Royal Caribbean's next Icon-class ship, due in 2027
- MSC World Atlantic, due in 2027
Our ship records are updated as new ships are delivered. Want to know how old each line's fleet is? Read our ranking of the oldest and newest cruise fleets.
Source: Cruise Frog ship data, as of Oct. 25, 2026. Gross tonnage and guest counts as recorded in our catalog.