Larry Fraser, 49, stole the limited edition print belonging to the street artist’s Girl With Balloon series after breaking into the Grove Gallery in Fitzrovia, central London, last September.
Sentencing him on Friday, Judge Anne Brown said: “This is a brazen and serious non-domestic burglary.”
Kingston Crown Court heard Fraser, who pleaded guilty to one count of burglary, may be eligible for immediate release due to time spent on electronic curfew.
The artwork had been part of an exhibition showcasing a £1.5 million collection of 13 Banksy pieces at the gallery and was quickly recovered by officers from the Metropolitan Police’s Flying Squad.
The defendant, of Beckton, east London, was seen on CCTV waiting outside the gallery for about 10 minutes on September 8 last year, before repeatedly smashing the glass door with a heavy blunt object, Philip Stott, prosecuting, told the court.
He said when Fraser gained access to the building, at about 11pm, he went straight to the artwork, which was a signed and numbered print.
Mr Stott said: “The defendant was taken to a location in London Docklands and the artwork was secreted inside a building there.
“It was later recovered shortly after, on September 12, after information was passed to the police by a third party.”
The value of the print, which was returned without damage, was approximately £270,000, he said.
A second man, 54-year-old James Love, was cleared of stealing the print following a trial, after he was accused of being the getaway driver in the burglary.
The court heard Fraser had put forward a basis of plea in which he stated he owed money to others due to a historic drug debt he was struggling to settle and agreed to commit the offence “under a degree of pressure and fear”.
He said he did not know the target of the burglary until the day of the offence and did not know its value.
Judge Brown said: “Whilst you did not know the precise value of the print, you obviously understood it to be very valuable.”
She added: “Whilst I am sure there was a high degree of planning, this was not your plan.”
She said the offence was “simply too serious” for a suspended sentence.
The court heard Fraser had 18 previous convictions but the most recent was in 2002, when he was jailed for robbery and unlawful wounding, and he had been “out of trouble” since his release from prison in 2008.
Jeffrey Israel, defending, said Fraser, who lived with his mother as her principal carer, had managed to “break his cycle of drug addiction” after his last prison sentence.
He said it “would take a bold advocate” to suggest that the value of the print had increased by what happened to it, but added: “That is probably the reality.”
Detective Chief Inspector Scott Mather, from the Met Police’s Flying Squad, said: “Banksy’s Girl with Balloon is known across the world – and we reacted immediately to not just bring Fraser to justice but also reunite the artwork with the gallery.
“The speed at which this took place is a testament to the tireless work of the Flying Squad officers – in total it took just four days for normality to be restored.”
Grove Gallery manager, Lindor Mehmetaj, 29, thanked police for recovering the work.
He said: “I was completely, completely shocked, but in a very, very positive way when the Flying Squad showed me the actual artwork.
“It’s very hard to put into words, the weight that comes off your shoulders.
“The way that they dealt with it from the moment they arrived on the scene: pragmatic, logical, very composed and ultimately professional.
“But also, to have the artwork recovered after it had been robbed from us is remarkable.”