[2] Following an inaugural Europe season, she debuted in North America in New York in November 2000[6][7] before re-positioning in December to Port Everglades in Fort Lauderdale, Florida to sail cruises in the Caribbean through the winter.

[10][11] In May 2011, a female passenger in her sixties was declared missing when she failed to disembark at a port call in San Diego.

[20] In summer 2021, Celebrity Millennium joined Celebrity Edge in becoming the second ship in its fleet to re-start North American Operations, offering few sailings out of St. Maarten prior to being repositioned to Seattle were in July 23 she became the 2nd ship worldwide to resume Alaska sailings.

[21] Millennium's original hull livery featured a predominantly dark blue paint with yellow and white bands lining the vessel.

[25] In July 2007, the ship's propellers were damaged after striking a submerged rock during an electrical malfunction near Villefranche-sur-Mer, forcing the cancellation of numerous Mediterranean sailings.

[8] In August 2013, the ship encountered problems with the electrical parts of the pods' motors that caused the cancellation of her remaining Alaskan sailings and forced an emergency dry dock for repairs in September 2013.

[27] Numerous repairs that proved unsuccessful led Royal Caribbean to file a lawsuit against Rolls-Royce and Alstom in August 2003 for $300 million to recover lost revenue and the costs associated with the pods.