Fairfield is a city in western Jefferson County, Alabama, United States.

It is part of the Birmingham metropolitan area and is located southeast of Pleasant Grove.

This city was founded in 1910 in which the featured speaker at the dedication ceremony was former President Theodore Roosevelt.

The name was later changed to the city in which the President of U.S. Steel lived, Fairfield, Connecticut.

It was planned as a model city by the Tennessee Coal, Iron and Railroad Company to house workers in their new Fairfield Works plant, now owned by U.S. Steel, similar to its northeastern city of Ensley.

[5] According to the U.S. Census Bureau, the city has a total area of 3.5 square miles (9.1 km2), all land.

As of the 2020 United States census, there were 10,000 people, 4,441 households, and 2,532 families residing in the city.

Though the United States' steel-making industry has gone through a decline through the last half of the 20th century, U.S. Steel's Fairfield Works continues to be a major employer, though not in the levels seen around the 1950s.

Advances in steel-making technology have enabled the works to produce roughly the same amount of product as during that era, but with a much smaller workforce.

Portions of the works have been closed over the years, but many parts of the complex have been reopened by smaller industries, some of which are steel-related.

The city's downtown area features a number of small businesses, primarily service-related.

All public bus transportation was terminated in July 2016 for failure to pay the bill.