The man, 21, from Balby, was stopped after Operation Fortify officers noticed the smell of cannabis coming from his car on 10 February on Woodfield Road.
Within the driver’s door, officers located the Rambo-style knife.
PC Emma Fothergill said: “Every single knife we take off the streets is a weapon that could otherwise be used to incite fear, or harm a member of the community.
“Fortify is the name of the overarching operation for tackling organised crime. Our role is to disrupt criminals and tackle drugs and violence associated with these networks.
“Proactive patrols enable us to inspect any suspicious vehicles, carry out stop and searches and take weapons off the streets, like we have on this occasion.”
He has been reported to the Crown Prosecution Service for possessing an offensive weapon in public.