Schettino was not in court when the verdict was read out by presiding judge Grazia D'Onofrio shortly after 8:30pm (1830 GMT).
He will not be jailed immediately pending a possible further appeal and Italy's crammed jails and generous parole system mean it is unlikely he will ever serve anything like 16 years in jail.
Schettino was sentenced in February 2015 to 16 years and one month in prison after a judge ruled that his recklessness was to blame for the fate of the giant ship, which struck underwater rocks off the Tuscan island of Giglio.
He was convicted of multiple manslaughter, causing a maritime accident and abandoning ship before all passengers and crew had been evacuated, earning him the nickname "Captain Coward" in the press.
The violation of the ancient code of the sea which states a captain must be the last man off a sinking ship only accounted for one year of the sentence handed down by a three-judge panel in the Tuscan town of Grosseto.
During the first, 19-month trial, Schettino was accused of showing off when he steered the ship too close to the island while entertaining a female friend.
The ship had been carrying more than 4,200 people, including 3,200 tourists. The bodies of two of the victims have never been found.
Schettino's lawyers had insisted the accident and its deadly consequences were primarily due to organisational failings for which the ship's owner, Costa Crociere, its Indonesian helmsman and the Italian coastguard should have shared the blame.
They also argued that it was not the collision, but rather the chaos that ensued due to the ship losing power that was the direct cause of the deaths. Schettino could not be blamed for the mechanical failures, they said.
Costa Crociere avoided potential criminal charges by accepting partial responsibility and agreeing to pay a €1 million ($1.2 million) fine.
Five of its employees received non-custodial sentences after concluding plea bargains early in the investigation.
They included the ship's Indonesian helmsman, who could have averted the disaster but did not understand an order given by Schettino to change course just before the collision.
The ex-captain's lawyer said he would have liked the man at the helm to be questioned further "but he cannot be found, he has disappeared into thin air".
Survivors who rejected Costa's initial compensation offer and became civil parties in the Schettino case were awarded an average of €30,000 each.
Among those awarded a payout were Domnica Cemortan, the blonde Moldovan dancer with whom Schettino had dinner just before the ship hit the rocks.
On top of his original prison term, Schettino was banned from public office for life and from working as a ship captain for five years.