More than 200,000 displaced people returned to north Gaza on foot in the two hours after the crossing opened, according a Gaza security official speaking to the AFP news agency.
Checkpoints for cars opened at 09:00 local time (07:00 GMT), two hours after foot crossings reopened - but, there's a report of delays for vehicles, according to AFP.
The news agency also says Gaza's government has employed "more than 5,500" people to "facilitate the return of displaced people" to Gaza City and the north.
Government estimates suggest people in Gaza City and the north need 135,000 tents and caravans as they return to destroyed homes.
Bd-pratidin English/Lutful Hoque