Established in 1935 as an extension from North Carolina. US 501 replaced part of US 117 between Myrtle Beach and Socastee, then from there through Conway, Marion, and Latta on what was SC 38. North of Latta, it overlapped with US 301, through Dillon, and into North Carolina.
During the 1940s, because of the need for a more direct route to Myrtle Beach Air Force Base from Conway, 2-lane US 501 was built through the Buist Tract owned by Southern Kraft Company (later part of International Paper), replacing SC 503, its old alignment was renumbered to SC 544. In 1950, US 501 was moved onto new construction between Conway and Aynor, its old alignment renumbered to SC 319. By 1964, US 501 was moved to its current southern bypass from downtown Conway, creating US 501 Bus. By 1990, US 501 was moved to its current eastern bypass from downtown Marion, creating another US 501 Bus.
In 2021, the South Carolina Department of Transportation and Horry County announced plans to spend tens of millions of dollars expanding U.S. 501 into four lanes each way near Myrtle Beach.
When US 501 was established in 1927, it was aligned along North Carolina Highway 13 (NC 13) from Durham north through Roxboro to the Virginia state line.