Lincoln Regional Airport (ICAO: KLHM, FAA LID: LHM, formerly O51) (Karl Harder Field) is a public airport three miles (5 km) west of Lincoln, in Placer County, California. It is owned by the City of Lincoln.

Most U.S. airports use the same three-letter location identifier for the Federal Aviation Administration and International Air Transport Association, but Lincoln Regional Airport is LHM to the FAA and has no IATA code.