Direct proof of use
The direct ZPU-1 evidence for the Syrian Civil War is a photographed captured-equipment listing. Oryx's November 2014 inventory of Islamic State captures inside Syria lists one 14.5 mm ZPU-1 under anti-aircraft guns and says the list includes captured vehicles and equipment for which photo or video evidence was available.
The source supports Islamic State possession or capture of a ZPU-1 in Syria by November 2014. It does not establish a specific firing event, target, battle damage claim, unit, or chain of custody for the gun.
Sources: Oryx Islamic State Captured Equipment Syria
Timeline
By November 2014, Islamic State forces had seized large quantities of Syrian military equipment during the expansion phase of the war. Oryx published its Syria inventory on 10 November 2014 and included one ZPU-1 among a wider set of anti-aircraft guns, artillery, armored vehicles, trucks, missiles, radars, and aircraft-related materiel documented in captured-equipment imagery.
Because the ZPU-1 entry is an inventory item rather than an incident report, the dated milestone for this page is the publication and evidence window, not a confirmed first operational use date.
Sources: Oryx Islamic State Captured Equipment Syria
Battlefield role
The ZPU-1 is a single-barrel Soviet 14.5 mm KPV-based anti-aircraft mount. WeaponSystems.net describes it as a light two-wheel mount that can be used from a towed carriage or carried on vehicles, and notes that post-Cold War technical mounting made it attractive mainly for ground-support use.
For this Syrian Civil War record, the safest role is captured or recovered anti-aircraft materiel held by Islamic State and jihadist groups. The general ZPU-1 design supports why such a weapon could matter on Syrian battlefields, but the Syria-specific source does not prove that this particular captured gun was fired from a technical or used in an air-defense engagement.
Sources: ZPU-1 WeaponSystems.net, Oryx Islamic State Captured Equipment Syria