Royal Caribbean said all passengers will receive full refunds. It sailed from there Sunday on a seven-day Caribbean cruise.
Passengers complained the ship was in "complete chaos" after they were forced to stay on board when the vessel docked in Falmouth, Jamaica.
Torres says returning a day early gives the cruise line "more time to completely clean and sanitize the ship" before it sails again. Oasis will miss the Mexico stop.
Since 2001, half of all outbreaks were caused by a new strain of the highly contagious norovirus.
"We are bringing additional medical staff on board and we're engaging in intensive sanitary procedures to minimize the risk of any further issues", a statement from Royal Caribbean said.
Cruise ships often get attention when they have a norovirus outbreak because they are expected to report them to the Centers for Disease Control and Prevention any time the amount of passengers affected surpasses 2 percent of the total passenger count.
"They are held to a standard that, frankly, not everyone else is held to", said Colleen McDaniel, senior executive editor of Cruise Critic, a popular cruise review website. The CDC is required publish data on the Outbreak Updates for International Cruise Ships portal maintained by the agency where 3% or more of passengers or crew report symptoms of gastrointestinal illness to the ship's medical staff.
"As of today, 167 cases of gastrointestinal illness have been reported since Sunday, representing 2 percent of the almost 9,000 guests and crew on board", spokesman Owen Torres told the outlet.
Every year, about a dozen mass norovirus outbreaks are cataloged by the CDC.
"People are still getting sick", he told ABC News.
It is not yet known what caused the outbreak, but most instances of norovirus occur in food service settings like restaurants, according to the CDC.
"I'm still having a good time", he said.