Agua Dulce is a census-designated place in Los Angeles County, California, United States. It lies at an elevation of 2,526 feet, northeast of Santa Clarita. The community had a population of 3,342 at the 2010 census and covers a geographic area of about 23 square miles. Agua Dulce is on the Pacific Crest Trail. The ZIP code is 91390, and the area code is 661.