Rausing, 49, also received a two-month suspended sentence for driving under the influence of drugs and was ordered to complete a residential drug rehabilitation programme, to start immediately, officials said.
Eva Rausing's body was found in advanced state of decomposition July 9 after her husband was stopped and arrested on suspicion of driving under the influence of drugs. Drugs and drug paraphernalia were found in his car.
After questioning Rausing, police found his 48-year-old wife's body under piles of clothing and plastic bags in the couple's luxury apartment in West London's Chelsea district. Authorities believe she died in early May.
The cause of death remains undetermined for the American-born daughter of a wealthy Pepsi executive. Officials have said an autopsy showed cocaine and amphetamines in her system.
Eva Rausing had entered a drug-rehabilitation programme in California before returning to London in April, according to news reports.
Judge Richard McGregor-Johnson told Rausing his behaviour was "an illustration of the utterly destructive effects of drug misuse."
The judge said that despite the advantages of wealth enjoyed by Rausing and his wife and periods of rehabilitation, "Your relapse into the misuse of drugs, together with that of your wife, destroyed all that."
In a statement read in court, Rausing said he had been "traumatised" by his wife's death and did "not have a very coherent recollection of events leading up to and since Eva's death. ... I tried to carry on as if her death had not happened and batted away any inquiries about her."
Rausing's lawyer, Alexander Cameron, brother of Prime Minister David Cameron, reportedly told the court Rausing acted "when as Shakespeare would put it, the balance of his mind was disturbed."
Gary Dolby, head of homicide for the prosecutor's office in London, said in a statement:
"Mr. Rausing has well-documented personal problems which no doubt contributed to his actions in the weeks following his wife's death. However, he went to some lengths to conceal her body despite numerous opportunities to tell someone what had happened.
"This resulted in Mrs. Rausing's family being unaware of her death for some time after it happened.
"His actions were unlawful and it is right that he now has a criminal conviction."
