A dry county is a county in the United States whose government forbids the sale of any kind of alcoholic beverages. Some prohibit off-premises sale, some prohibit on-premises sale, and some prohibit both. Dozens of dry counties exist across the United States, a majority of them in the South. A number of smaller jurisdictions also exist, such as cities, towns, and townships, which prohibit the sale of alcoholic beverages. These are known as dry cities, dry towns, or dry townships. Dry jurisdictions can be contrasted with "wet" (minimal alcohol prohibitions) and "moist" (fewer prohibitions than "dry" but more than "wet").
Although the 21st Amendment repeals nationwide prohibition in the United States, it allows for prohibition under state or local laws. Prior to and after repeal of nationwide prohibition, some states passed local option laws granting counties and municipalities, either by popular vote or ordinance, the ability to decide for themselves whether to allow alcoholic beverages within their jurisdiction. Many dry communities do not prohibit the consumption of alcohol, which could potentially cause a loss of profits and taxes from the sale of alcohol to their residents in wet (non-prohibition) areas.
The rationale for maintaining prohibition at the local level is often religious in nature, as many evangelical Protestant Christian denominations discourage the consumption of alcohol by their followers (see Christianity and alcohol, sumptuary law, and Bootleggers and Baptists). In Utah, while state law does not allow for dry counties, laws designed to restrict the sale and consumption of alcohol are common in (but not exclusive to) this mostly LDS (Mormon) state. Consumption of alcohol is discouraged by the LDS Church.
Since the 21st Amendment repealed nationwide prohibition in the United States, alcohol prohibition legislation has been left to the discretion of each state, but that authority is not absolute. States within the United States and other sovereign territories were once assumed to have the authority to regulate commerce with respect to alcohol traveling to, from, or through their jurisdictions. However, one state's ban on alcohol may not impede interstate commerce between states that permit it. The Supreme Court of the United States held in Granholm v. Heald that states do not have the power to regulate interstate shipments of alcoholic beverages. Therefore, it may be likely that municipal, county, or state legislation banning possession of alcoholic beverages by passengers of vehicles operating in interstate commerce (such as trains and interstate bus lines) would be unconstitutional if passengers on such vehicles were simply passing through the area. Following two 1972 raids on Amtrak trains in Kansas and Oklahoma, then dry states, the bars on trains passing through the two states closed for the duration of the transit, but the alcohol stayed on board.
A 2004 survey by the National Alcohol Beverage Control Association found that more than 500 municipalities in the United States are dry, including 83 in Alaska. 36 of the 82 counties in Mississippi are dry or partially dry. In Florida, three of its 67 counties are dry, all of which are located in the northern part of the state, an area that has cultural ties to the Deep South.
Moore County, Tennessee, the home county of Jack Daniel's, a major American producer of whiskey, is a dry county, so the product is not available at stores or restaurants within the county. The distillery does sell commemorative bottles of whiskey on site.
A study in Kentucky suggested that residents of dry counties have to drive farther from their homes to consume alcohol, thus increasing impaired driving exposure, although it found that a similar proportion of crashes in wet and dry counties are alcohol-related.
Other researchers have pointed to the same phenomenon. Winn and Giacopassi observed that residents of wet counties most likely have "shorter distances (to travel) between home and drinking establishments." From their study, Schulte and colleagues postulate that "it may be counter productive in that individuals are driving farther under the influence of alcohol, thus, increasing their exposure to crashes in dry counties."
Data from the National Highway Traffic and Safety Administration (NHTSA) showed that in Texas, the fatality rate in alcohol-related accidents in dry counties was 6.8 per 10,000 people over a five-year period. That was three times the rate in wet counties: 1.9 per 10,000. 
Another issue a dry city or county may face is the loss of tax revenue because drinkers are willing to drive across city, county or state lines to obtain alcohol. Counties in Texas have experienced this problem, which led to some of its residents to vote towards going wet to see their towns come back to life commercially. Although the idea of bringing more revenue and possibly new jobs to a town may be appealing from an economic standpoint, religious opposition remains present.
One study finds that the shift from bans on alcohol to legalization causes an increase in crime. The study finds that "a 10% increase in drinking establishments is associated with a 3 to 5% increase in violent crime. The estimated relationship between drinking establishments and property crime is also positive, although smaller in magnitude."
Dry and moist counties in Kentucky had a higher rate of meth lab seizures than wet counties.
During the eight-year run of The Andy Griffith Show and the subsequent three-year run of Mayberry R.F.D., the fictional Mayberry County, North Carolina, where Mayberry was located, was established to have been a dry county. A running gag on the show portrayed the Otis Campbell character as constantly ending up in jail due to his drunkenness. Otis was drunk so often, he would let himself into his regular jail cell using a key stored within reach of the jail's two comfortable cells and sleep off the effects of alcohol. Many plots would also involve out-of-town criminals committing alcohol-related crimes, such as running moonshine in Mayberry. In reality the only county in North Carolina that is completely dry is Graham County, which is on the Tennessee border.