Celebrity Millennium completed an approximately $8 million refurbishment at Victoria Shipyards, introducing the Rooftop Terrace on Deck 12 with outdoor cinema screenings, cabanas, lounge seating, decorative lighting and the Taste of Film dining experience. The Olympic specialty restaurant was converted into Tuscan Grille, an Italian-inspired steakhouse, while historic maritime artifacts from the former restaurant were relocated to a display near the casino entrance. Penthouse and Royal Suites received upgraded bathroom fixtures, marble surfaces, seating, carpeting, curtains and bedding. The Solarium was refreshed with new furniture, flooring and refinished pool surfaces, while the Spa Café received updated finishes. Additional improvements included removal of themed casino décor, installation of an enclosed portrait studio and creation of a dedicated future cruise sales office.

Celebrity Millennium underwent an emergency dry dock at Grand Bahama Shipyard following repeated electrical failures in its starboard Rolls-Royce Mermaid propulsion pod during its Alaska cruise season. The failures forced the early termination of two voyages and cancellation of four additional sailings. The principal repair involved removing the defective 250-ton azimuthing propulsion pod and installing a replacement transported from Europe aboard a specially chartered cargo vessel. The operation required coordinated work by Rolls-Royce engineers, shipyard technicians and specialist contractors to disconnect the damaged unit, position the replacement, reconnect mechanical and electrical systems, and complete propulsion testing and safety certification. Additional onboard work included deep cleaning of stateroom furnishings, upholstery, draperies and carpeting, along with relocation of the Future Cruise Sales Office from Deck 3 to the Deck 5 shopping area.

Celebrity Millennium completed an extensive three-week transformation at Grand Bahama Shipyard as the fourth and final Millennium-class vessel to undergo Celebrity Cruises' $140 million “Solsticizing” fleet-renewal program. The project added new staterooms and introduced 107 AquaClass accommodations with access to the new Blu restaurant, while Celebrity Suites received new private verandas. New Solstice-class venues included Qsine, Celebrity iLounge, Bistro on Five, Café al Bacio and Gelateria, Cellarmasters, and the Martini Bar and Crush. Public spaces and accommodations received extensive new carpeting, upholstery, furnishings and décor, while shipwide Wi-Fi and other technology were upgraded.