The newest and most advanced class of ships in the Princess Cruises fleet is the Sphere Class. The flagship of this class, the Sun Princess, debuted in early 2024, followed by its sister ship, the Star Princess, which launched in late 2025. These ships are the largest ever built for Princess and are powered by Liquefied Natural Gas (LNG), making them the line's most environmentally friendly vessels. The Sphere Class is defined by its revolutionary architectural features, most notably "The Dome," a glass-enclosed top-deck entertainment space inspired by the terraces of Santorini, and "The Sphere," a suspended glass Piazza that offers stunning panoramic ocean views. In 2026, these ships are headlining major itineraries in the Caribbean, Mediterranean, and Alaska, representing a significant "next-gen" leap for the brand.