It sentenced seven others to “life imprisonment with hard labour”, amounting to 25 years each.
It published details of the defendants, detained between 2017 and 2019, claiming some had provided information on Hamas members' homes and contact details, as well as the location of tunnels and rocket launch sites to Israeli authorities.
Hamas, which has ruled the blockaded enclave since 2007, regularly sentences people convicted of collaborating with Israel to death.
Some of the alleged collaboration dates back more than two decades, according to the interior ministry.
In September, it executed two Palestinians for collaborating with Israel, as well as three others for murder.
In April, two people were sentenced to death and four others were given life sentences on the same charge.
At least 17 death sentences were issued last year.
The militant group has largely ignored a ruling which requires death sentences to be approved by the president of the Palestinian Authority, headquartered in the Israeli-occupied West Bank.
One defendant, from the Bureij refugee camp, is said to have collaborated with Israel since 2007 after being contacted by an intelligence officer, the interior ministry said.
Another is said to have worked with Israel from 2011 to 2018 and received money in exchange for information on Hamas members, identifying their homes and cars and the location of missile launch sites.
One man under sentence of death was convicted for contact with Israel in 1996 after meeting an intelligence officer at the Beit Hanoun crossing, which connects Gaza to Israel.
Israel and Hamas have fought several wars since it took power.
Some 2.3 million Palestinians live in the Gaza Strip, which has been under a harsh Israeli-led blockade since the militant group took over.
Rare demonstrations last week came amid increasing dissatisfaction with Hamas rule, which has done little to relieve the daily suffering of Gaza's residents.
“One of the major monuments of corruption in Gaza is that the people are living under siege and the leaders of Hamas are living in palaces abroad,” protest organiser Rami Herzallah told The National.