Louisiana Highway 59 is a state highway located in St. Tammany Parish, Louisiana. It runs 11.74 miles in a north–south direction from U.S. Highway 190 in Mandeville to LA 21 north of Abita Springs.
Signage on the eastbound I-12 ramp to LA 59 directs travelers confusing the route with I-59, located about 20 miles (32 km) farther east, to get back onto I-12 eastbound.