MSC Cruises’ MSC Virtuosa was the first ship to welcome passengers at the terminal.
The facility is fitted with shore power, allowing vessels with the necessary technology to "plug in" once it is commissioned later this year.
Last year, Associated British Ports announced the new £55 million multi-user terminal in partnership with MSC Cruises and Norwegian Cruise Line Holdings.
Alastair Welch, director of ABP Southampton, said the "next-generation-ready" terminal would strengthen the port’s position as "Europe’s leading cruise turn-around port".
"We’re incredibly proud to be building the infrastructure for the future of cruise with a commitment to sustainable operations," he added.
"We marked the UK restart of cruise with MSC Virtuosa leaving the port with the first passengers on 20 May and we’re excited to announce this next significant milestone for the future of cruise in the Port of Southampton."
