The guilty verdicts for multiple manslaughter and negligence were the first reached in the sinking of the cruise liner carrying more than 4,000 crew and passengers near the Tuscan shore in January 2012.
The ship's captain, the only remaining defendant, was denied a plea bargain and is being tried separately. He faces up to 20 years, if convicted of manslaughter, causing the shipwreck and abandoning the ship.
On Saturday, lawyers representing the 32 victims of the shipwreck said the sentences of the plea bargain - a fraction of what is usually handed down for manslaughter - were inadequate given the gravity of the disaster.
"It seems like a sentence for illegal construction," said lawyer Massimiliano Gabrielli. "It's an embarrassment."
Another lawyer for victims, Daniele Bocciolini, called the sentences "insufficient" and questioned the prosecutors' hypothesis placing the lion's share of the blame on Capt. Francesco Schettino.
The five employees of the Costa Crociere SpA cruise company were charged for their respective roles in the nautical maneuver that put the ship in peril, evacuation and response to the emergency.
The longest sentence went to the company's crisis coordinator, who was sentenced to two years and 10 months. Concordia's hotel director was sentenced to two years and six months, while two bridge officers and a helmsman got sentences ranging from one year and eight months to one year and 11 months.
The bridge officials and helmsman were also convicted of a charge of causing a shipwreck, in addition to multiple manslaughter and negligence.
The court's reasoning for its decision will be released within 90 days, as is standard in Italy.
Prosecutors accused the crisis coordinator, who wasn't aboard the ship, of downplaying the severity of the emergency and delaying adequate response, while the hotel director was charged for his role in the evacuation, described by passengers as chaotic.
The helmsman was blamed for steering the ship in the wrong direction after Schettino ordered a corrective maneuver.
Prosecutor Francesco Verusio said the convictions confirmed investigators' version of events.
"I don't think there are any more doubts about the responsibility that falls above all on the shoulders of Schettino," Verusio said.
Schettino is charged with manslaughter for causing the shipwreck off the Tuscan island of Giglio and abandoning the vessel with thousands aboard. That trial opened this week, and was continued after two hearings until the end of September.
The Concordia, on a week-long Mediterranean cruise, speared a jagged granite reef when, prosecutors allege, Schettino steered the ship too close to Giglio's rocky shores as a favor to a crewman whose relatives live on the island. Schettino has denied the charges and insisted that the rock was not in nautical maps.
The reef sliced a 70-meter-long (230-foot) gash in the hull. Seawater rushed in, causing the ship to rapidly lean to one side until it capsized, then drifted to a rocky stretch of seabed just outside the island's tiny port.
Survivors have described a delayed and confused evacuation. The bodies of two victims were never found, but they were declared dead after a long search.
Barry contributed from Milan.