The community was named Red Oak Junction by the railroad on March 20, 1876.

Darwin R. Merritt, born in Red Oak on April 12, 1872, graduated third in his class from the United States Naval Academy in Annapolis, Maryland on July 1, 1897.

On February 15, 1898, he perished in the explosion that sank the USS Maine (ACR-1) in the harbor of Havana, Cuba.

His body was later recovered and interred in Evergreen Cemetery in Red Oak.

In the American Civil War, the area provided more Union troops per capita than any other in the state.

[8] Company M (which also included residents from Montgomery County) had 160 casualties among its 250 members; 52 men were killed in action.

[5] Early World War II battles claimed a disproportionate number of soldiers from Red Oak, although the final casualty statistics tend to disprove the oft-repeated statement that Red Oak suffered more losses per capita than any other American community.

[8][9][10] In the Battle of Kasserine Pass in February 1943, forty-five soldiers from Red Oak alone were captured or killed;[11] more than 100 telegrams arrived in Red Oak saying that its soldiers were missing in action.

[7] In recognition of Red Oak's casualties, the city's name was given to a "victory ship".

[12] The SS Red Oak Victory has become a floating museum in the shipyard where it was built, in Richmond, California.

Hispanic or Latino persons of any race comprised 5.5% of the population.

36.9% of all households were made up of individuals, 18.1% had someone living alone who was 65 years old or older.

The Montgomery County Memorial Hospital (MCMH) is located in Red Oak.

MCMH is a modern 25-bed facility with birth to hospice capabilities.

In 1961 a long-term care unit, named Highland Acres, was constructed.

In 1978 in a special election voters approved of Montgomery County taking ownership of Murphy Memorial Hospital.