Ludlow is an unincorporated rural hamlet in Harding County, South Dakota, United States.

It is located on Federal Highway 85, approximately 21 miles north of Buffalo, the Harding County seat, and six miles south of the North Dakota border.

Although not tracked by the Census Bureau, nor having a post office, Ludlow has been assigned the ZIP code of 57755 by the United States Postal Service.

Heavily isolated, the town is located over 20 miles away from the nearest grocery store and gas station.

The only business in operation is a bar, The Crooked Creek #1,[1] which is frequently visited by travelers to and from Sturgis.