The UK is imposing sanctions on 49 people and organisations behind the most "notorious" human rights abuses of recent years.
Individuals implicated in the death of Russian lawyer Sergei Magnitsky in 2009 will have their UK assets frozen and banned from entering the country, the BBC reported.
And Saudi Arabian officials involved in the 2018 murder of journalist Jamal Khashoggi are also being targeted.
Foreign Secretary Dominic Raab said the move sent a "clear message."
Speaking in the Commons, the foreign secretary said the UK was taking action against the "thugs of despots and henchmen of dictators" as well as stopping those trying to launder their "blood-drenched ill-gotten gains."
Russia has threatened to retaliate with reciprocal measures and said the sanctions were "pointless."
"Russia reserves the right to respond to today's unfriendly decision by the UK on the basis of reciprocity," the Russian embassy in London said in a statement, adding that the move "will not improve Russian-British relations."
The sanctions are the first taken independently by the UK outside the auspices of the UN and EU.
Those individuals and organisations subject to immediate sanctions are:
- 25 Russian nationals involved in the mistreatment and death of lawyer Sergei Magnitsky, who uncovered widespread corruption by a group of Russian tax and police officials
- 20 Saudi nationals involved in the death of journalist Jamal Khashoggi in the Saudi consulate in Istanbul
- Two high-ranking Myanmar military generals involved in the systematic and brutal violence against the Rohingya people and other ethnic minorities
- Two organisations involved in forced labour, torture and murder in North Korea's gulags
Raab said those targeted had been involved in extra-judicial killings, including political assassinations, torture, degrading treatment, forced labour and servitude.
Those on the list, which includes a former minister in the Russian interior department and the former deputy head of the Saudi intelligence services, will be stopped from entering the UK, channelling money into the country or profiting from the British economy, through property or other assets they own.