The peculiar incident occurred in North Yorkshire when officers stopped a Peugeot 206 on suspicion of driving with two bald tyres.
Upon inspecting the vehicle, the officers discovered an unusual passenger in the boot.
When questioned, the driver told police he was taking it to a nearby McDonald’s.
A spokeswoman for North Yorkshire Police said: “He told the officer, ‘some people take their dogs in their cars, I take my sheep’.
“He [the motorist] just wanted to go for a drive-through at McDonalds.”
The driver is thought to have been stopped shortly after a visit to the fast food restaurant at Leeming Bar services on the A1 in North Yorkshire.