Hamas fighters killed at least 1,400 people and kidnapped about 220 others in the attack, according to Israeli officials. Four hostages have since been released.
The demonstrators in Tel Aviv sang songs and held placards with pictures of those missing and feared kidnapped, and the words “Bring them home now”.
At one point, air raid sirens blasted, forcing people to run to the car pack below. Blasts were heard as the air defence systems kicked into action.
Miri Benami, a 44-year-old mother of Yosef Ohana, 24, who had attended the festival near where the attack on southern Israel occurred, says she has prayed that her son comes home.
She said the government had recently informed her that his status had been changed from missing to kidnapped.