An Okie is a person identified with the state of Oklahoma, or their descendants. This connection may be residential, historical or cultural. For most Okies, several (or all) of these connections exist and are collectively the source of their being Oklahoman. While not an official demographic used or recognized by the United States Census Bureau, Okies, due to various factors, have developed their own distinct culture within larger social groupings both akin to and separate from Midwestern and Southern influences. Included are their own dialect, music, and Indigenous-derived folklore.

In California, the term came to refer to very poor migrants from Oklahoma coming to look for employment. The Dust Bowl and the "Okie" migration of the 1930s brought in over a million migrants, many headed to the farm labor jobs in the Central Valley. A study in the 1990s indicated that about 3.75 million Californians were descendants of this population. By 1950, four million individuals, or one quarter of all persons born in Oklahoma, Texas, Arkansas, or Missouri, lived outside the region, primarily in the West.

Prominent Okies included singer/songwriter Woody Guthrie and country musician Merle Haggard. John Steinbeck wrote about Okies moving west in his Pulitzer Prize-winning 1939 novel The Grapes of Wrath, which was filmed in 1940 by John Ford.

In the mid-1930s, during the Dust Bowl era, large numbers of farmers fleeing ecological disaster and the Great Depression migrated from the Great Plains and Southwest regions to California mostly along historic U.S. Route 66. Californians began calling all migrants by that name, even though many newcomers were not actually Oklahomans. The migrants included people from Oklahoma, Arkansas, Missouri, Iowa, Nebraska, Kansas, Texas, Colorado and New Mexico, but were all referred to as "Okies" and "Arkies". More of the migrants were from Oklahoma than any other state, and a total of 15% of the Oklahoma population left for California.^{[citation needed]}

Ben Reddick, a free-lance journalist and later publisher of the Paso Robles Daily Press, is credited with first using the term Okie, in the mid-1930s, to identify migrant farm workers. He noticed the "OK" abbreviation (for Oklahoma) on many of the migrants' license plates and referred to them in his article as "Okies". The first known usage was an unpublished private postcard from 1907.

Once the Okie families migrated from Oklahoma to California, they often were forced to work on large farms to support their families. Because of the minimal pay, these families were often forced to live on the outskirts of these farms in shanty houses they built themselves. These homes were normally set up in groups called Squatter Camps or Shanty Towns, which were often located near the irrigation ditches which ran along the outskirts of these farms. Indoor plumbing was inaccessible to these migrant workers, and so they were forced to resort to using outhouses. Unfortunately, because of the minimal space allotted to the migrant workers, their outhouses were normally located near the irrigation ditches, and some waste would inevitably runoff into the water. These irrigation ditches provided the Okie families with a water supply.

Due to this lack of sanitation in these camps, disease ran rampant among the migrant workers and their families. Also contributing to disease was that these Shanty Town homes that the Okie migrant workers lived in had no running water, and because of their minimal pay medical attention was out of the question. However, what native Californians failed to realize at the time was that these Okie migrant farm workers did not always live in the conditions that the Dust Bowl left them in. In fact, often these families had once owned their own farms and had been able to support themselves. This meant that Okie families often had been in a fairly comfortable situation before the circumstances surrounding the Dust Bowl induced their migration.

Historian James Gregory has explored the long-term impact of the Okies on California society. He notes that in The Grapes of Wrath, novelist John Steinbeck envisioned the migrants becoming active unionists and New Deal agitators demanding higher wages and better housing conditions. Steinbeck did not foresee that most Okies would move into well-paid jobs in war industries in the 1940s. When a man named Oliver Carson visited Kern County in the 1930s, he became fascinated with the Okie culture and lifestyle. He travelled back in 1952 to see what the Okies had made of themselves and saw that the difference was astounding. They were not living in roadside encampments anymore or driving run-down cars- they had better living situations and better views on life.