Clarksville is an unincorporated community in Baltimore Hundred, Sussex County, Delaware, United States located just west of Millville.

Many tourists from the Baltimore–Washington metropolitan area pass through the town on their way to and from the Delaware Beaches.

[3] The Blackwater Presbyterian Church and Spring Banke near Clarksville are listed on the National Register of Historic Places.

[7] Clarksville formerly had a post office with a ZIP code of 19937; however, the post office closed and the ZIP code was discontinued.

[8] Clarksville is currently served by the Ocean View post office with a ZIP code of 19970.