Halltorps hage is a nature reserve on the island of Öland in Borgholm Municipality, Kalmar County, Sweden.

The nature reserve serves to protect an area with varied deciduous forest.

At the heart of the reserve is a pasture dominated by several large oaks.

Other trees found in the reserve include ash, linden, maple and hornbeam.

Flowers such as spring vetchling, yellow anemone and the unusual Veronica montana grow in the nature reserve.