Highway 138 may refer to:
Canada Ontario Highway 138 Prince Edward Island Route 138 Quebec Route 138
Costa Rica National Route 138
India National Highway 138 (India)
Japan Japan National Route 138 Fukuoka Prefectural Route 138 Nara Prefectural Route 138
Malaysia Malaysia Federal Route 138
United Kingdom road B138 road
United States U.S. Route 138 Alabama State Route 138 County Route 138 (Lee County, Alabama) Arkansas Highway 138 California State Route 138 Connecticut Route 138 Florida State Road 138 (former) County Road 138 (Columbia County, Florida) County Road 138 (Gilchrist County, Florida) County Road 138A (Lafayette County, Florida) County Road 138 (Pinellas County, Florida) Georgia State Route 138 Hawaii Route 138 Illinois Route 138 K-138 (Kansas highway) Kentucky Route 138 Louisiana Highway 138 Maine State Route 138 Maryland Route 138 Massachusetts Route 138 M-138 (Michigan highway) Missouri Route 138 New Jersey Route 138 New Mexico State Road 138 New York State Route 138 County Route 138 (Herkimer County, New York) County Route 138 (Niagara County, New York) County Route 138 (Onondaga County, New York) North Carolina Highway 138 Ohio State Route 138 Oregon Route 138 Pennsylvania Route 138 Rhode Island Route 138 Rhode Island Route 138A Tennessee State Route 138 Texas State Highway 138 Texas State Highway Spur 138 Farm to Market Road 138 Utah State Route 138 Utah State Route 138 (1933-1953) (former) Virginia State Route 138 Virginia State Route 138 (1930-1933) (former) Wisconsin Highway 138 Wyoming Highway 138 (former)
Territories Puerto Rico Highway 138