Stafford County sheriff's spokesman Bill Kennedy said the man stole the milk from the Walmart in Garrisonville about 10:35 p.m. Tuesday, the Manassas News and Messenger reported Thursday.
Kennedy said witnesses reported seeing the man distributing the milk to passersby outside the store.
It was unclear Thursday how the man was able to get 26 gallons of milk outside.
Deputies said they responded a short time later to a call about a disturbance at a nearby McDonald's and spotted an 18-year-old man who matched the description of the suspect. The man, whose name was not released, was found to have a cow suit in his car.