The incident was reported Sunday on the Lily Cache Creek Trail, according to Bolingbrook police. The trail is currently closed until further notice.
The coyote snarled and nipped at the woman's heels, but neither she nor the dog were injured, police say.
Authorities say coyotes are generally fearful of humans and will try to avoid contact, but will protect their dens and pups if they feel threatened.
If you come into contact with a coyote, authorities say you should not attempt to run, but yell at it to make the coyote back off.
Coyotes are protected under Illinois wildlife code.