Interstate 126 (abbreviated I-126) is a spur route of Interstate 26, almost entirely within the city limits of Columbia, South Carolina in the United States. It runs 3.1 miles (5 km) from I-26 just south of the junction with Interstate 20, eastward across the Broad River (Timmerman Bridge), and into downtown Columbia terminating at US 21/US 176/US 321 (Huger Street). It is named the Lester Bates Freeway and is co-signed with US 76 for the entire route.

I-126 has unnumbered interchanges with Colonial Life Boulevard (westbound only), Greystone Boulevard, and US 21/US 176/US 321. The route is seven lanes from I-26 to Colonial Life Boulevard and eight lanes to US 21/US 176/US 321. Two lanes extend into Columbia signed as "I-126/US 76 EAST - Elmwood Avenue" but the freeway ends within the US 21/US 176/US 321 interchange.

Westbound Elmwood Avenue (US 21/US 76/US 176/US 321) was also signed as Interstate 126 Business for several decades but this designation never appeared on maps. By 2006, only one sign retained the "Business Spur" designation and, by 2008, all such signs had been replaced by standard interstate signs.

The entire route is in Columbia, Richland County. All exits are unnumbered.