The trucks carrying supplies entered Idlib province through the Cilvegözü border gate in Turkey's south.
The aid will be distributed among residents of Idlib and nearby rural areas.
Syria has been ravaged by civil war since early 2011 when the Bashar Assad regime cracked down on pro-democracy protesters.
Hundreds of thousands of people have been killed and more than 10 million displaced, according to U.N. estimates.
Idlib falls within a de-escalation zone forged under an agreement between Turkey and Russia.
The province has long been under siege by the Assad regime's forces and its allies, and previous cease-fires in the region have been plagued by violations. The province's population had gradually increased as many people have fled from regime attacks and oppression by terrorist groups. The displacement of civilians has intensified since mid-December, however, when the Russian-backed Assad regime started a new assault to seize the last opposition bastion. It is estimated that over 1 million Syrians have moved near the Turkish border due to intense attacks over the last year, while half of these Syrians were displaced after November 2019.
As tensions heightened, Russia and Turkey in March reached an agreement to halt the violence and the flow of displacement. As part of their deal, military activities were stopped in Idlib and a 6-kilometer (3.7-mile) security corridor was established along the critical M4 highway. Since the cease-fire, relative calm has prevailed in the region, while Turkey and Russia have been conducting joint patrols along M4.
While humanitarian aid was delivered to Syria previously through four border crossings, Russia closed the ar-Ramtha border crossing between Syria and Jordan, and al-Yarubiyah with Iraq last year.
In July, the number of gates for aid deliveries between Turkey and Syria reduced from two to one. For the next year, only the Bab al-Hawa border crossing opposite Cilvegözü will remain open for aid delivery for another year.