It is located at the intersection of Ohio State Route 4 and 161.

[3] Irwin has a post office which serves the surrounding area, including the community of Rosedale.

[4] The community was named for one Mr. Irwin, a pioneer settler.

[5] Located near Irwin is Elmwood Place, a historic farm that is listed on the National Register of Historic Places.

This Union County, Ohio state location article is a stub.