The park's namesake, Colonel O'Fallon, came to St. Louis after being severely wounded at the Battle of Tippecanoe in the War of 1812, and became assistant to his uncle William Clark of the Lewis and Clark Expedition. The park was a part of a vast 600 acre land holding of Colonel John O'Fallon.
The park is highly visible from I-70 so most in the region know O'Fallon Park from the rolling hills and mature trees just east and south of Bellefontaine Cemetery.
This is a popular fishing spot with fishermen on all sides of the lake. There is a planted island in the middle of the lake, and chess tables and planters between the lake and the boathouse.
The walking path is extensive and extremely well used. There are spots along the track that include the commonly seen blue workout stations. There are functional water fountains and bike racks near the trail.
One of the amazing new developments is a handicap accessible playground installed in 2014. This one precedes the one currently under construction in Willmore Park.
The park has tennis courts, football field (with field goals) and basketball courts as well, all in excellent condition.
There are several picnic pavilions.
O'Fallon Recreation Complex; complete with outdoor pool and water slides.