Mr Johnson made the astonishing attack in his weekly column for the Sunday Telegraph.
He claimed: “It was entirely deliberate.
“It seems likely that the Saudi state, whoever was ultimately responsible, has copied the playbook of Vladimir Putin, and the attempted killing of Sergei and Yulia Skripal.”
Jamal Khashoggi, a Saudi journalist who wrote for The Washington Post, was killed in the Saudi consulate in Istanbul on October 2.
When his disappearance was reported, Saudi officials initially denied any knowledge of his fate, but later claimed he had been killed after a brawl broke out in the building between the journalist and “rogue elements” of Saudi Arabia’s security forces.
However, according to media reports, he was murdered, tortured and dismembered by a 15-strong Saudi hit squad.
Mr Johnson was clear the UK should take firm action in response to the killing.
He said: “Both the UK and the US must lead other countries in holding Saudi Arabia properly to account.
“The body must be produced. The audio tape of the killing said to be held by the Turkish authorities should be made public.
“The UK should prepare to sanction those involved in carrying out or authorising the brutal killing of this journalist, not least since journalists are now being killed at an unprecedented rate.”
Mr Johnson also made a direct comparison between the murder of Mr Khashoggi and the poisoning of Sergei and Yulia Skripal.
He said: “In the Salisbury atrocity and the Khashoggi murder we therefore seem to have events of a type: state-sponsored plots to execute opponents on foreign soil.
“The very outlandishness of the modus operandi is intended to send a terrifying public warning to every expatriate journalist or dissident who dares to oppose the regime.”
He concluded: “The killing of Khashoggi was a barbaric act to which we in Britain refuse to turn a blind eye.”
On March 4, Sergei and Yulia Skripal were poisoned in Salisbury in an attempted murder which the UK has blamed on the Russian state.
In June, two UK nationals, Dawn Sturgess and Charlie Rowley, were poisoned with the same nerve agent and Ms Sturgess subsequently died.