The University of California, Irvine, Arboretum (or UCI Arboretum) is a 12-acre botanical garden and arboretum, located north of the University of California, Irvine campus. It is near at the corner of Jamboree Road and Campus Drive in Irvine, California, and adjacent to the 200-acre San Joaquin Freshwater Marsh Reserve . The Arboretum is open to the public six days a week, Monday-Saturday, 9 a.m. to 3 p.m., and free of charge.

The Arboretum was first established in 1964 as a nursery and holding area to supply UCI with landscaping plants. It is now dedicated to preserving rare and endangered plant species from California, ranging from the Channel Islands to the native grasslands. More broadly, the Arboretum collects plants from around the world that are suited to southern California's Mediterranean climate, including aloes, native cacti, and South African perennials.