Gabis Arboretum at Purdue Northwest is a nature preserve near Valparaiso, Indiana in the United States.

The preserve has the largest collection of oak trees in Indiana and an award winning garden railway.

[1] In December 2017 the Gabis family announced that Purdue University Northwest would assume operation of the arboretum, with the name change and management effective January 31, 2018.

The property includes a prairie, woodlands, wetlands, savanna, and plant collections and display gardens.

[2] There is a garden railway onsite, which comprises a 2.5 acre G scale model railroad intertwined with plants.