Like the three previous Wish vessels, Believe will have a signature them shaping the onboard experience, from the entertainment to the venues and decor.
Previous themes include enchantment, adventure, and heroes and villains; Believe's theme will be "promise and possibilities".
The ship will feature worlds inspired by Encanto and Frozen, the wishing wells from Snow White and the Seven Dwarfs, and the sea life from Moana and The Little Mermaid.
DCL said Believe would arrive during "an exciting moment of optimism and transformation for the company", adding it would honour "the dreamers and doers who dare to pursue their own happily ever after".
With the addition of Believe, the DCL fleet will grow to 13 ships by 2031, with a new class of ship due to be introduced in 2029. DCL also plans to introduce trips to Japan that same year.