New South is a term that has been used intermittently since the American Civil War to describe the American South, in whole or in part. The term "New South" is often used in contrast to the Old South of the antebellum period.

The term has been used with several different applications in mind. The original use of the term "New South" was an attempt to describe the rise of a South after the Civil War which would no longer be dependant on the now-outlawed slave labor or predominantly upon the raising of cotton, but rather a South which was also industrialized and part of a modern national economy. Henry W. Grady made this term popular in his articles and speeches as editor of the Atlanta Constituition. For many years, this "New South" was more of a slogan of Chambers of Commerce and similar civic-booster organizations than a reality in many areas.

The beginnings of the Civil Rights era in the 1950s led to a revival of the term to describe a South which would no longer be held back by Jim Crow laws and other aspects of legal segregation. Again, the initially-slow pace of the Civil Rights era reforms, notably in the areas of school desegregation and voting rights, at first made the "New South" more of a slogan than a reality; the Civil Rights Act of 1964 and the Voting Rights Act of 1965 brought an era of far more rapid change.

A third usage of the term "New South" has been in the area of politics. This "New South" has a competitive two-party political system. For over 100 years, from before the Civil War until the mid-1960s, the Democratic Party totally dominated Southern politics. Thus elections were actually decided between Democratic factions in primary elections (often all-white); the Democratic nomination was considered to be "tantamount to election". The "New South" period in this context really began in 1964 when several Southern politicians supported Republican Barry Goldwater for President in lieu of Democratic incumbent Lyndon B. Johnson; some, in what later became a trend, switched party affiliations, notably Strom Thurmond of South Carolina. Richard Nixon's Southern strategy of 1968 is thought by many to have vastly accelerated this process. Now the South is generally solidly Republican at the Presidential level unless the Democratic nominee is from the South, in which case it may be competitive; however, at the local level the Democratic Party is still overwhelmingly dominant in some, if not most, regions of the South.

The term "New South" is also sometimes used geographically, to denote the South Atlantic states, in contrast to the East South Central and West South Central states. The former have grown considerably more cosmopolitan and ethnically diverse in recent decades, and many observers maintain that they now comprise a distinct geocultural subregion. One prominent example of the use of "New South" in this context was in the 1991 book The Day America Told The Truth, which divides the South as a whole into the "moral regions" of the New South and Old Dixie.