Direct proof of use
The MiG-25 is documented in the 2011 Syrian Civil War through Bellingcat's January 2015 review of the Syrian Arab Air Force. The report said a rebel video released on August 8, 2012 confirmed that some MiG-25s might still have been operational at Tadmur, commonly known as Palmyra.
Bellingcat gave the clearest direct-use incident in 2014: it reported that MiG-25s reappeared in March and April, and that a MiG-25PD(S) fired two infrared-homing R-40TD air-to-air missiles at Aqaribat in Hama Governorate. The same account said one missile failed after ground impact and the second exploded in the air, followed by additional R-40 launches in the same period.
Sources: The Syrian Arab Air Force, Beware of its Wings
Timeline
By the start of the civil war, much of Syria's MiG-25 fleet had been phased out. Bellingcat described many decommissioned aircraft visible at T4 in November 2013, while also noting evidence that a smaller number may still have been operational.
The published conflict-use sequence is therefore short: a 2012 rebel video at Palmyra, reappearances in March and April 2014, and multiple R-40 missile launches in 2014. Air & Space Forces Magazine separately described Syria as having about 30 flyable MiG-25 Foxbats in early 2013, giving contemporary background for why the aircraft still mattered in no-fly-zone and air-superiority discussions.
Sources: The Syrian Arab Air Force, Beware of its Wings, The Syria Question
Narrative
In Syrian government service, the MiG-25 was not a routine close-air-support aircraft. Its documented civil-war appearance was tied to a small surviving fleet of interceptors, reconnaissance-bombers, and trainers after much of the type had been retired or stored.
The Aqaribat incident shows an unusual wartime role: an interceptor variant using R-40TD air-to-air missiles against a ground area. Bellingcat treated the practice as ineffective, reporting repeated failed launches and questioning what the Syrian Arab Air Force expected to achieve with air-to-air missiles used this way.
The public record also leaves several limits. Bellingcat discussed possible MiG-25RB bombing potential and eyewitness claims of high-altitude air raids near Khan al-Sheeh, but those claims were less direct than the named R-40 missile launches at Aqaribat. This record therefore treats the MiG-25's Syrian Civil War role as limited missile attack and residual operational use by the Syrian government, not as a broad bombing campaign.
Sources: The Syrian Arab Air Force, Beware of its Wings, The Syria Question