British Air Force Typhoon FGR4s have operated alongside French aircraft in a combined operation against an underground arms cache in Syria operated by the IS group, according to the UK Ministry of Defence.
The site, identified by surveillance, was thought to be containing munitions and bombs, the release indicated, and was situated in mountains just above the historic site of Palmyra in central Syria.
"Our aircraft used precision-guided Paveway IV munitions to strike a series of approach shafts down to the facility... early reports are that the strike was effective," the MoD said.
There was no indication of any civilian impact in the strike late on Saturday and each participating jet returned safely, the defence officials confirmed.
The Typhoon fighters were supported by a Voyager refuelling tanker.
IS - also known as ISIS - enforced extremist governance over parts of Syria and Iraq prior to its 2019 collapse.
"This strike demonstrates British leadership, and determination to stand shoulder to shoulder with our allies, to stamp out any revival of Daesh and their violent and radical beliefs in the area," Britain's Defence Chief the minister said.
RAF aircraft have carried out patrols over Syria to "prevent any efforts to regroup" of Islamic State after its military defeat at the climactic battle in Baghuz in 2019, the MoD reported.
"I must thank the personnel of our armed forces involved in this strike for their expertise and their courage," he added. "They were among thousands of British personnel on duty over Christmas and New Year. This action, to remove terrorist threats who endanger our security, demonstrates how our armed forces are prepared to act, throughout the year, keeping Britain secure within its borders and strong abroad."
In December, the US military executed what it described as a "major assault" on Daesh sites in the country, following an ambush claimed the lives of two US servicemembers and a civilian interpreter in the Palmyra area.
The United Nations says Islamic State still maintains roughly 5-7 thousand combatants in Syria and Iraq.
