Poor White is a sociocultural classification used to describe economically disadvantaged Whites in the English-speaking world, especially White Americans with low incomes.

In the United States, Poor White is the historical classification for an American sociocultural group, of generally Western and/or Northern European descent, with many being in the Southern United States and Appalachia regions. They were first classified as a social caste in the Antebellum South, consisting of white, agrarian, economically disadvantaged laborers or squatters, who usually owned neither land nor slaves.

In the British Commonwealth, the term was historically used to describe lower-class whites, notably in the context of the "poor white problem" in South Africa.

Author Wayne Flynt in his book, Dixie's Forgotten People: The South's Poor Whites (2004), argues that "one difficulty in defining poor whites stems from the diverse ways in which the phrase has been used. It has been applied to economic and social classes as well as to cultural and ethical values." While other regions of the United States have white people who are poor, this does not have the same meaning as the Poor White in the South. In context, the Poor White refers to a distinct sociocultural group, with members who belong to families with a history of multi-generational poverty and cultural divergence.^{[citation needed]}

Throughout American history the Poor Whites have regularly been referred to by various terms; the majority of which are often considered disparaging. They have been known as "rednecks" (especially in modern context), "hillbillies" in Appalachia, "crackers" in Texas, Georgia, and Florida, "Hoosier" in St. Louis, Missouri, and "white trash". The use of the term "Poor White" by the white Southern planter class, was to distance themselves from elements of society they viewed as "undesirable", "lesser" or "antisocial."

Much of the character and condition of Poor Whites is rooted in the institution of slavery. Rather than provide wealth as it had for the Southern planter class, in stark contrast, slavery considerably hindered progress of whites who did not own enslaved individuals by exerting a crowding-out effect, eliminating free labor in the region. This effect, compounded by the area's widespread lack of public education and its general practice of endogamy, prevented low-income and low-wealth free laborers from moving to the middle class. The majority of whites in the Deep South who never owned African-American slaves were poor.

Many fictional depictions in literature used poor whites as foils in reflecting the positive traits of the protagonist against their perceived "savage" traits. In her novel Dred, Harriet Beecher Stowe illustrates a commonly held stereotype that marriage to them results in genetic degradation and barbarism of the better class.

During the American Civil War, the Poor White comprised a majority of the combatants in the Confederate Army; afterwards, many labored in the rural South as sharecroppers. During the nadir of American race relations at the turn of the 20th century, intense violence, defense of honor and white supremacy flourished in a region suffering from a lack of public education and competition for resources. Southern politicians of the day built on conflict between Poor Whites and African Americans in a form of political opportunism. As John T. Campbell summarizes in The Broad Ax in 1906. The Civil War also caused poor whites to experience intense dire economic conditions and was brought into poverty along with enslaved African-Americans.