In Mississippi, I-55 runs 290.5 miles from the Louisiana border near Osyka to Southaven on the Tennessee border, just south of Memphis. The highway parallels U.S. 51 during its trek roughly through the center of Magnolia State.
The Mississippi section of Interstate 55 is defined in Mississippi Code ¡ì 65-3-3.
I-55 is often called the Mississippi Delta Highway because of its proximity to the Mississippi River.