Odessa was founded in 1881 as a water stop and cattle shipping point on the Texas and Pacific Railway. The first post office opened in 1885. Odessa became the county seat of Ector county in 1891 when Ector County was first organized. It became an incorporated city in 1927, after oil was discovered in Ector County on the Connell Ranch southwest of Odessa.

With the opening of the Penn Field in 1929, and the Cowden Field in 1930, oil became a major draw for new residents. In 1925, the population was just 750; by 1929, it had risen to 5,000. Due to increased demand for oil during the second world war, the city's population had expanded to 10,000.