Mississippi is served by 17 rail lines, including five Class I carriers – two of which run directly through Harrison County.
- CSX – Class 1 carrier serves Harrison County, from Mobile on the east and New Orleans on the west
- Kansas City Southern – Class 1 carrier runs north-south through Stone and Harrison counties to the Mississippi State Port at Gulfport and is adjacent to the new Global Axis Industrial Park
- Port Bienville Rail – located in Hancock County and runs between CSX and Port Bienville Industrial Park
- Southern – Class 1 carrier runs through Pearl River County to New Orleans
- Norfolk Southern – runs through Pearl River County to New Orleans
- Pearl River Valley – local carrier that connects to the Norfolk line
- Illinois Central – Class 1 carrier crosses through George County between Hattiesburg and Mobile
- Mississippi Export – local carrier that runs north-south through George and Jackson counties
