Dunlay is an unincorporated community in Medina County, Texas, United States. It lies about six miles west of Castroville and eight miles east of Hondo on U.S. Highway 90. The town was named after Jerry Dunlay, a local train conductor. Dunlay, which was originally called Enterprise, was established in 1881 along the Galveston, Harrisburg and San Antonio Railway. A post office was established in 1890 with Norval Seymour Murray as postmaster.