Vicky Cherry, 44, had been missing for 15 months when police found her body wrapped in a duvet and plastic sheeting at a house in Toronto Street, Bolton, in January.
Andrew Reade, 43, admitted preventing the lawful burial of a body and perverting the course of justice.
He was sentenced at Bolton Crown Court to four years and four months in jail.
Miss Cherry's cause of death could not be ascertained because of heavy decomposition but a pathologist concluded she may have died as a result of strangulation, as injuries to her neck were detected.
Sentencing Reade, Judge Timothy Clayson said the defendant could not be held responsible for Miss Cherry's death but what followed was "inexcusable".
Officers had launched a "non-body" murder investigation because Miss Cherry, from Fulwood, Lancashire had not been seen since October 2015.
Reade, of Toronto Street, Bolton, told her family they had split up and she had moved to Blackburn. However, police discovered that her unemployment benefits were still being withdrawn in Bolton.
When officers arrested Reade on suspicion of murder, he claimed he had panicked upon waking to find his girlfriend dead after they had binged on a cocktail of drugs.
The 43-year-old admitted hiding her body and lying to her family and police. He also admitted taking her benefits for several months after her death.
In a victim statement to the court, Miss Cherry's daughter said: "Reade has held her body in a cupboard with things on top of her like she was a piece of rubbish.
"I will never forgive Reade. Reade himself is the only person who truly knows what happened to my mother. We will be forever tormented by this."
Nick Ross, defending, said his client, a long-standing user of Class A drugs, had exercised "very poor judgment" after grief and panic had set in following Miss Cherry's death.
"He wishes he could turn the clock back," he said.
Det Ch Insp Terry Crompton said: "Reade's deliberately deceptive and misleading actions seriously obstructed the investigation into how Vicky died and cost us valuable opportunities to investigate."
A man who hid his dead girlfriend's body in an airing cupboard for more than a year has been jailed.