"Business 37" is the name given to the most extreme northern and southern parts of Walnut Street in Bloomington. It unofficially begins on the north side at the intersection of Walnut and Old State Road 37 and continues north for almost 2 miles until it merges with SR 37 at the small interchange where the road begins. Some could argue that "Business 37" begins when Walnut meets The Bypass.
On the south side of town, "Business 37" unofficially begins when Walnut Street meets Fairfax Road, very near the area of Clear Creek and Walnut's meeting with 37 on the south side. It continues south for almost 2 miles until it reaches 37 at a stoplight. The road then continues on as the southern spur of Old State Road 37 for appox. 8 miles until it reaches 37 at a stoplight again in Lawrence County.
Landmarks passed on both spurs of "Business 37":
- Bloomington/Monroe County Visitors Center (north spur)
- Bloomington Valley Nursery (south spur)
- Bloomington Speedway (near start of south spur)
- Mays Greenhouse (south spur)