Delmar Boulevard starts at North 14th Street in Downtown St. Louis, as a westward extension of Convention Plaza.

After about two miles, Delmar crosses Interstate 170, where it has an interchange (Exit 2), before coming to an end at Price Road shortly thereafter.

Delmar is often considered to represent a major socioeconomic divide in the city, having come to demarcate the poorer, largely African American neighborhoods located to the north from the more affluent (and largely white) ones to the south; this phenomenon is called the "Delmar Divide".

The old right-of-way still exists as an alley and is marked as "Hodiamont Streetcar R-O-W" or "Suburban Track" on many maps of the area.

In 2009, the portion of Delmar within the city of St. Louis was given the honorary name of Barack Obama Boulevard to honor the newly elected president.