The agreement faced a legal challenge taken up by Albania's Constitutional Court following condemnation from opposition parties in both countries, as well as rights groups.
"The agreement does not harm Albania's territorial integrity," the court said in a statement.
The Tirana court ruling comes just days after Italian MPs voted in favour of the agreement. The lower chamber of parliambackedent the protocol by 155 votes to 115, with two abstentions.
During the parliamentary debate, opposition MPs accused Prime Minister Giorgia Meloni of using migrants as "electoral propaganda", saying the project would have little impact on numbers and was hugely costly.
The text now goes to the Italian Senate, where it is also expected to be approved.
The accord allows for two centres to be established near the Albanian port of Shengjin, where migrants would register for asylum, as well as a facility in the same region to house those awaiting a response to their applications.
The two centres – to be managed by Italy – can hold a maximum of 3,000 people at any one time, while they await a decision on their claims.
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They estimated the cost at more than €650 million ($703m) over the five-year term of the accord.
The right-wing opposition in Albania has lambasted Prime Minister Edi Rama for an alleged lack of transparency over the agreement, calling the deal an "irresponsible and dangerous act for national security".
The International Rescue Committee NGO has condemned the agreement as "dehumanising", while Amnesty International described it as "illegal and unenforceable".
Albanian authorities have said the agreement is in line with previous treaties signed with Italy, with international law and the country's constitution.
"We are not selling a piece of land of Albania," Interior Minister Taulant Balla told AFP during an interview last month.
"We are offering this land to Italy like we usually do for example when we set up an embassy."
Jurisdiction inside the camp would be Italian, but the land would remain in Albanian hands, he added.
Italy will pay to build the two centres and necessary infrastructure, as well as expenses relating to the security and medical care of asylum seekers, according to Albanian authorities.
Ms Meloni – leader of the far-right Brothers of Italy party – was elected to office in 2022 promising to stop migrant boats arriving from North Africa.
However, official figures show numbers have risen from around 105,000 migrant landings in 2022 to almost 158,000 in 2023.