Icon of the Seas has 19 total decks, with deck numbers running up to 20 because there is no Deck 13.

Most sources also note that:

  • 18–19 of these are considered passenger decks, depending on how they classify technical/crew areas.
  • Around 11–12 decks contain guest cabins, with the rest used for pools, entertainment, dining, and neighborhoods like Central Park and the Royal Promenade.

So if you’re asking “Icon of the Seas how many decks,” the clear headline answer is: 19 decks in total, numbered 2 through 20 (no 13).