HRL may refer to: HRL (software), an artificial intelligence program named for mathematicians Hardy, Ramanujan and Lakatos HRL, a Rockwell scale of materials' hardness HRL Laboratories, formerly Hughes Research Laboratories, in Malibu, California, United States Harlech railway station, in Wales Hilandar Research Library of medieval Slavic manuscripts, at Ohio State University, United States IBM Haifa Research Laboratory, in Haifa, Israel Valley International Airport (IATA airport code), serving Harlingen, Texas, United States