Delcastle Technical High School is a public vocational-technical high school in unincorporated New Castle County, Delaware, near Wilmington, and is the largest of four high schools within the New Castle County Vocational-Technical School District, which includes Howard High School of Technology in Wilmington, Hodgson Vo-Tech High School in Glasgow, and St. Georges Technical High School in St. Georges. It houses the administrative offices of its respective school district.