Direct proof of use
The 9K720 Iskander appears in the 2011 Syrian Civil War as a Russian-operated tactical ballistic missile system used during Russia's intervention on the Syrian government-and-allies side. Newsru, summarizing Sergei Shoigu's remarks at a Russian Ministry of Defence collegium on December 22, 2017, reported that Russian forces used the Iskander operational-tactical missile system in Syria alongside Tochka-U, Kalibr, and Kh-55 missiles.
A second public confirmation followed in December 2018. CSIS Missile Threat reported that Russian Deputy Prime Minister Yury Borisov said the Iskander-M had proved effective in the Syrian war, and Defence Blog reported the same Borisov statement as confirmation that Russia used Iskander-M during combat operations in Syria.
Sources: Newsru Shoigu Syria Report, CSIS Iskander Syria Confirmation, Defence Blog Iskander Syria Confirmation
Timeline
Open-source reporting first placed Iskander-related vehicles at Russia's Hmeimim airbase area before the formal official-use acknowledgments. Defense Update reported that an Iskander transporter-erector-launcher was first seen in Russian Zvezda television footage in March 2016, and later ImageSat International satellite analysis showed Iskander-system vehicles at Hmeimim in Latakia.
On January 6, 2017, CSIS Missile Threat reported that EROS B satellite imagery showed at least two road-mobile SS-26 Iskander launchers at the Syrian army's Latakia airbase and assessed that the launchers were believed to be manned and operated by Russian forces. The December 2017 and December 2018 Russian official statements then moved the record from deployment reporting to acknowledged combat-use reporting.
Sources: Defense Update Hmeimim Iskander, CSIS Satellite Spots Iskander, Newsru Shoigu Syria Report, CSIS Iskander Syria Confirmation
Operational role
The documented role was long-range ground-launched strike capability under Russian control in support of the Syrian government-and-allies side. The selected sources support Russian deployment, Russian operation, and Russian official claims of use or battlefield effectiveness; they do not identify a complete launch log, specific firing units, individual target coordinates, or independently verified impact sites for each Iskander round fired in Syria.
In this conflict record, the Iskander should be separated from Syrian government ballistic-missile use and from Iranian ballistic-missile strikes in eastern Syria. The Iskander evidence here points to Russian expeditionary forces at the Hmeimim/Latakia base network and to Russian officials describing combat use during the Syria operation.
Sources: CSIS Satellite Spots Iskander, Defense Update Hmeimim Iskander, Kings College Russian Military Presence, Newsru Shoigu Syria Report, CSIS Iskander Syria Confirmation