The delegation, headed by Sir Gerald Kaufman, a veteran British MP, is the biggest in years to visit Gaza.
The parliamentarians represent 12 European countries and include Lord Ahmed, Jeremy Corbyn, Baroness Tonge and Clare Short, a former UK international development secretary.
The delegation will meet Amr Moussa, the secretary-general of the Arab League, as well as other Egyptian officials, to discuss the humanitarian condition in Gaza, in light of the continued siege imposed by Israel.
The organisation has already sent a number of boats carrying humanitarian aid for the besieged population.
Hamas, the group that controls the Palestinian territory, estimates that 1,600 people were killed during the war.
Other estimates put the death toll closer to 1,400, the majority of whom were civilians, including around 400 children.
Thirteen Israelis were also killed during the war.
A UN-sponsored report, known as the Goldstone report, called on both Israel and Hamas to investigate accusations of human-rights violations committed during the conflict.
Most of the criticism in the report was directed towards Israel.
It concluded that Israel had used disproportionate force and had deliberately targeted Gaza civilians, using them as human shields, while destroying civilian infrastructure.