Deer Park was founded in 1892 by Simeon H. West, a farmer, retired legislator, and much-traveled adventurer from Illinois.

[4] The subdivision was established in 1893 and was the site of a Galveston, Harrisburg and San Antonio Railway station by about 1894.

By 1922, Deer Park had dwindled down to almost nothing with four houses, one little schoolhouse, and an old hotel with a few scattered shacks along the railroad right-of-way.

By 1946, however, the area began to flourish as Deer Park became the site of refineries and toluene plants for the production of TNT.

[5] The citizens of Deer Park voted to incorporate on December 12, 1948, and a few weeks later Earl E. Dunn became the first mayor.

Deer Park has a school district with 14 campuses, a city library, community theater, municipal court building, three fire stations, numerous city parks and recreational facilities, state-of-the-art water and sewer processing facilities, a post office, several hotels, 14 major industries as well as several light industrial companies.

Deer Park is near the site of the Battle of San Jacinto, where, on April 21, 1836, Texas won its independence from Mexico.

Because the initial surrender treaty after the battle was drafted in Dr. George Moffitt Patrick's cabin, Deer Park bills itself as the "Birthplace of Texas".

The Texas State Historical sign marker was relocated from the Dow Chemical parking lot to the replica log cabin home of Dr. Patrick located at the Theatre/Courts Building.

On June 22, 1997, an ethylene explosion occurred at the nearby Shell Chemical Company plant that was heard and felt as far as 25 miles (40 km) away.

While no evacuation of the city was ordered, residents living within a mile west of the plant were advised to remain inside their homes.

The tanks involved in the fire contained chemicals including xylene, naptha, pyrolysis gasoline (Pygas), and toluene.

[15] In May 2023, a Shell petrochemical plant in Deer Park, causing a three-day blaze that resulted in toxic contamination in the air and water.

[19] Deer Park is bounded by the city of La Porte to the south and east, and by the Houston Ship Channel—the dredged-out Buffalo Bayou—to the north.

Deer Park Post Office is located at 200 East San Augustine Street.