The staunch critic of President Vladimir Putin almost died in a nerve agent attack last year.
The UK is imposing asset freezes and travel bans on seven Russian nationals linked to the poisoning of Russian opposition leader Alexei Navalny.
Mr Navalny – a staunch critic of President Vladimir Putin – almost died from a nerve agent attack last year.
He accused Mr Putin of ordering the attack, something the Kremlin denies.
The UK Foreign Office said the sanctions, taken with the US, targeted those “directly responsible for planning or carrying out the attack”.
All seven of the individuals targeted are members of the Russian Federal Security Service (FSB), it added.
Foreign Secretary Dominic Raab said: “We are sending a clear message that any use of chemical weapons by the Russian state violates international law, and a transparent criminal investigation must be held.
“We urge Russia to declare its full stock of Novichok nerve agents.”
The term Novichok – “newcomer” in Russian – applies to a group of nerve agents developed in a lab by the Soviet Union during the Cold War. They paralyse muscles and can lead to death by asphyxiation.
Mr Navalny, 45, was exposed to one such nerve agent on a flight from Tomsk, Siberia, to Moscow on 20 August 2020. By the time the plane landed, he could not speak and was taken directly to hospital.
He was later transferred to a hospital in Berlin, Germany, where he spent a further 32 days recovering, including 24 days in intensive care.