Bača pri Modreju is a village in the Municipality of Tolmin in the Littoral region of Slovenia. It lies at the confluence of the Bača River with the Idrijca River, which in turn joins the Soča River at Most na Soči, northwest of the settlement. The village includes the hamlets of Grapa, Stopec, and Sopotnica.

The Municipality of Tolmin is a municipality in northwestern Slovenia. Its seat and largest settlement is Tolmin. It borders Italy.