Newton Municipal Airport (IATA: TNU, ICAO: KTNU, FAA LID: TNU) is a city-owned public-use airport located two miles (3 km) southeast of the central business district of Newton, a city in Jasper County, Iowa, United States.

Newton Municipal Airport covers an area of 304 acres (123 ha) which contains one runway designated 14/32 with a 5,599 x 100 ft (1,707 x 30 m) asphalt surface.

For the 12-month period ending September 12, 2007, the airport had 9,000 aircraft operations, an average of 24 per day: 93% general aviation and 7% air taxi.

At that time there were 21 aircraft based at this airport: 90% single-engine and 10% multi-engine.

[1] On September 17, 2011, Newton was scheduled to be the host of the annual Fly Iowa Airshow.