Symphony of the Seas is the second of two identical "Oasis 3" class cruise ships (the new “world’s largest” liners), together with its sister Harmony Of The Seas (launched in 2016). The Symphony ship exceeds in size the original Oasis-class vessels Oasis and Allure, and has building cost of USD 1,35 billion (2016 shiporder rates).
The ship's official delivery to RCI is scheduled for March 23, 2018. Symphony is the 13th vessel delivered to Royal Caribbean from STX France, as well as the fleet's 25th ship.