Ullin is a village in Pulaski County, Illinois, United States.

Ullin was established as a site along the Illinois Central Railroad in the mid-1850s.

Some sources suggest it was named for a Gaelic folk hero who frequently appears in the works of the poet Ossian.

The Cypress Creek National Wildlife Refuge lies to the east of Ullin.

38.9% of all households were made up of individuals, and 27.1% had someone living alone who was 65 years of age or older.