Louisiana Highway 59 (LA 59) is a state highway located in St. Tammany Parish, Louisiana. It runs 11.74 miles (18.89 km) in a north–south direction from U.S. Highway 190 (US 190) in Mandeville to LA 21 north of Abita Springs. The highway is the most direct connection between the city of Mandeville and the town of Abita Springs. It also connects both places with Interstate 12 (I-12) roughly halfway between the two. North of Abita Springs, LA 59 intersects LA 21, connecting to Bogalusa and points along the Louisiana–Mississippi state line.