The attack saw over 1,200 people killed and 251 others taken back to Gaza as hostages. It was the single deadliest day for Jews since the Holocaust.
Israel responded by launching a military offensive in Gaza which has killed more than 67,000 people, according to the territory's Hamas-run health ministry. Its figures are seen as reliable by the UN and other international bodies.
Prime Minister Benjamin Netanyahu said in a statement that alongside "immense pain", Israel had shown "miraculous resilience".
Our bloodthirsty enemies have hit us hard, but they have not broken us," Netanyahu said on Tuesday.
He vowed to "achieve all the goals of the war: the return of all the kidnapped, the elimination of the Hamas regime and the promise that Gaza will no longer pose a threat to Israel".
Recalling Hamas's attack on southern Israel two years ago, UN Secretary General António Guterres said: "The horror of that dark day will be forever seared in the memories of us all".
He also called on all parties to agree to US President Donald Trump's peace plan, describing it as a "historic opportunity" to "bring this tragic conflict to an end".
