The bombings took place only hours after last nights decision to take the fight to IS.
Four Tornados from RAF Akrotiri in Cyprus took part in the operation soon after MPs voted to approve bombing.
The strikes targeted the Omar oil fields in eastern Syria, which is under IS control, and were “successful”, Defence Secretary Michael Fallon said.
He had personally approved the targets ahead of the Commons vote, he said.
MPs overwhelmingly backed UK military action against IS – also known as Daesh – in Syria, by 397 votes to 223, after a 10-hour Commons debate on Wednesday.
Mr Fallon said the MoD would be assessing the damage done by the bombing later, but the aim was to strike “a very real blow on the oil and revenue on which Daesh depends”.
Many oppose, and many agree, it really is one of the political decisions of the century.
After a stormy ten hour debate, the House of Commons last night, ‘we’ (UK) have voted to join others such as France, the US and Russia in bombing targets in Syria. Some 397 MPs were in favour, and 223 against.
Mr Cameron called on MPs to “answer the call from our allies” and take action against the “woman-raping, Muslim-murdering, medieval monsters” of IS, who he warned were “plotting to kill us and to radicalise our children right now”.
He said MPs faced a simple question: “Do we work with our allies to degrade and destroy this threat and do we go after these terrorists in their heartlands from where they are plotting to kill British people, or do we sit back and wait for them to attack us?”