LSU Hilltop Arboretum, Botanical garden along Highland Road, Baton Rouge, United States.

The LSU Hilltop Arboretum covers 14 acres at 11855 Highland Road in St. George, Louisiana, on the outskirts of Baton Rouge. Emory Smith and his wife began planting it in 1929 as a garden laid out like a cathedral: grassy plots served as the nave and rooms, trees, shrubs and bamboo as the walls, and old tree trunks as the pillars. Its collection ranges from bamboo, beech, birch and camellia to live oak, magnolia, pecan and cypress.

Emory Smith and his wife began developing the arboretum in 1929 on their property along Highland Road. They donated it to Louisiana State University in 1981. The site lay in unincorporated East Baton Rouge Parish until St. George's city jurisdiction took effect on April 26, 2024, following a court decision.

The gardens display native Louisiana plants and trees, showing how the region's plant life grows and fits into the local landscape. Visitors can observe these species in settings that reflect their natural habitats throughout the state.

The arboretum is at 11855 Highland Road, in St. George with a Baton Rouge postal address, and is open free of charge during daylight hours seven days a week. The grounds cover 14 acres, so allow time to walk the paths between the planted areas.

The Smiths laid out the garden as a cathedral in plan: grassy plots served as the nave and rooms, trees, shrubs and bamboo as the walls, and old tree trunks as the pillars. The 14 acres were donated to Louisiana State University in 1981.