Officers from South Yorkshire Police stopped Torick Akram, 36, while he was driving in the Chapeltown area of Sheffield on May 6, last year.
Police conducted a search of his car and found two suitcases, containing an estimated £1.1 million inside.
After further investigations by the Yorkshire and Humber Regional Organised Crime Unit, Akram, of Thorpe Hesley, Rotherham, was charged with money laundering.
He pleaded guilty to the charge at an earlier court hearing at Sheffield Crown Court, and has now been jailed for four-and-a-half years.
Detective Inspector Mick Ryan, of the Regional Economic Crime Unit, said: “We welcome the sentence of Torick Akram who was stopped by police officers and found to be in possession of over one million pounds.
“This is a substantial recovery and confiscation proceedings have now started against Akram to ensure his full benefit from crime is identified and taken from him.”