[3] Newcastle became a dot on the map with the opening of a new post office March 26, 1894 and a population of 25.

The mail office was established on the Minco-to-Norman road in Section 11, Township 9 North, Range 4 West.

In 1905, postmaster Alonzo Haun moved the facility to his general store in Section 14, Township 9 North, Range 4 West.

In 1920 the town's post office was relocated one mile east on land donated for a public school and a church.

Soon after Japan surrendered, a tornado swept through Newcastle and destroyed the school and much of the business section.

[9] The limits of Newcastle essentially comprised the post office and school district until around 1960, when Oklahoma City began annexing huge chunks of land across the river.

Nearby Tuttle and Blanchard expanded as well to attempt to prevent Oklahoma City from trying to annex across the Canadian River.

In the 1980s, Newcastle annexed territory that lies near Norman, Oklahoma (north of State Highway 9).

Cotton, ranching, and the dairy industry, once important to the local economy, declined with subdivisions and commercial development taking over former agricultural lands.

At the end of the twentieth century the public school system was Newcastle's largest employer.

[11] April 25, 1893, a massive tornado, reportedly over a mile and a quarter wide at one point, moved northeast along a 15-mile path from northwest of Newcastle through what now is part of Moore, and swept away at least 30 homes.

On May 20, 2013, another violent tornado damaged parts of Newcastle, including the historic retired Ozark Trail Bridge, growing rapidly as it headed north crossing the Canadian River, and did a large amount of damage to neighboring Moore and southern Oklahoma City.

[1] Newcastle is considered to be part of a rapidly growing area of northern McClain and Grady counties.

School colors include a royal blue and black, with the mascot being a "Newcastle Racer".