The `Freedom` singer had previously pleaded guilty to driving while unfit through drugs and possessing two cannabis joints when he was caught slumped at the wheel of his car after crashing into a photography shop in Hampstead, north London, on July 4.
George - real name Georgios Panayiotou - was handed the custodial sentence at Highbury Corner Magistrates Court.
Four weeks of the sentence will be served in prison, while the remaining time will be spent under the supervision of the probation service.
The judge took into account the fact George had checked into a rehab clinic immediately after the incident and his charity work, but confirmed he had no choice but to jail the pop superstar.
At a court appearance in August he was banned from driving for six months and warned he could be sent to prison following a similar charge in 2007, in which he received a 100-hour community service order.
The incident happened after the 47-year-old singer had attended a Gay Pride event in central London.
George has found himself in trouble with the law on several occasions - in September 2008 he was caught in a public toilet in possession of crack cocaine and marijuana.