An air shuttle is a scheduled airline service on short routes with a simplified fare and class structure. No exact definition exists, but frequency is usually hourly or more often and travel time is typically an hour or less. Network airlines may operate shuttle services as one-class or no-frill services, similar to low-cost airlines.
Some shuttles are established by governments, businesses, or organizations which require a high level of service in an otherwise thin corridor. For example, the Federal Aviation Administration's William J. Hughes Technical Center in Atlantic City, New Jersey operates an air shuttle to ferry FAA employees to and from Reagan National Airport (DCA) near Washington, DC four days a week.
Certain dense markets may support commercial shuttles. The pioneer service was the Rio de Janeiro-São Paulo air bridge in Brazil which began 5 July 1959. Other early services include the Eastern Air Shuttle, inaugurated in 1961, which offered no-frills, hourly flights connecting LaGuardia Airport in New York City with Washington National Airport and Logan International Airport in Boston, Massachusetts.
Present-day commercial air shuttle services include:
- US Airways Shuttle
- Delta Shuttle
- Horizon Air service between Seattle Tacoma International Airport and Portland International Airport
- Japan Airlines and All Nippon Airways service between Tokyo (Tokyo International Airport, Narita International Airport) and Osaka (Osaka International Airport, Kansai International Airport, Kobe Airport) in Japan
- Air Canada RapidAir  service between Toronto and Montreal as well as Toronto and Ottawa in Canada. The route is also served by WestJet and Porter Airlines with up to 200 flights every weekday between the three cities.
- TAM, GOL and Varig's Ponte Aérea (Air Bridge) service between São Paulo and Rio de Janeiro in Brazil.
- Iberia Puente Aéreo service between Madrid and Barcelona in Spain every 30 minutes.
- Air France La Navette service offers 80 flights a day from Paris-Orly Airport to Marseille, Bordeaux, Nice, and Toulouse, with a flight every 30–60 minutes. This service is used by more than 5.6 million travellers every year.
- Qantas and QantasLink 'CityFlyer' service offers flights between major Australian capital cities on weekdays, with complimentary alcoholic afternoon drinks, newspapers, flexible fares and more frequent schedules.
- Air New Zealand operates about 20 flights every day from Auckland to Wellington and Christchurch (3 of New Zealand's largest cities) using a mix of Boeing 737-300s and Airbus A320s, with up to half-hourly services during peak hours. There are also approximately 15 daily flights between Wellington and Christchurch using a mix of their mainline jets and the turboprop regional aircraft operated by Air New Zealand Link.
- Korean Air, Asiana Airlines and other minor Korean airlines' service between Gimpo International Airport and Jeju International Airport. The busiest air route in Asia.
- Singapore Airlines, Malaysia Airlines and Silkair code-share a Kuala Lumpur- Singapore shuttle every hour.
- Scandinavian Airlines (SAS) and Norwegian Air Shuttle provide a shuttle service between the Norwegian airports of Oslo Airport, Gardermoen and Bergen Airport, Flesland; Trondheim Airport, Værnes and Stavanger Airport, Sola with up to 30-minute headways. Both companies also operate shuttle services, with up to hourly-headways, between Stockholm-Arlanda Airport and Gothenburg-Landvetter Airport, Stockholm Arlanda Airport and Malmö-Sturup Airport and between Copenhagen Airport and Aalborg Airport.
- SAS also has a shuttle on the triangular route between Oslo Airport, Gardermoen (Norway), Stockholm-Arlanda Airport (Sweden) and Copenhagen Airport (Denmark) with up to hourly headways.
- South African Airways, Kulula, Comair and Mango provide an air shuttle service between OR Tambo International Airport and Cape Town International Airport with up to half-hourly headways
- The routes between Hong Kong and Taipei, Taiwan (Republic of China), and between Hong Kong and Bangkok, Thailand, are served by multiple carriers providing frequent service with frequency less than an hour during day time.
- The route between Dublin and London is served by over 640 flights each week, with departures on average every 20 minutes in each direction. The majority of the flights are operated by Aer Lingus, Ryanair and British Airways but CityJet and FlyBE also operate on the route.
- Aeroflot has a frequent service between the cities of Moscow and Saint Petersburg in Russia.
- Alitalia makes about 60 flights per day between Rome Fiumicino and Milano Linate Airport in a service called ROMAMILANO. At the two airports the check-in counters and security checkpoints are reserved for the passengers of this service.
- Turkish Airlines, Pegasus Airlines, Atlasjet and Onur Air 64 daily flight between İstanbul Atatürk Airport and Izmir Airport. This route is the second-busiest route in Europe.
The busiest air routes in the world involve pairs of large cities in close proximity that rely on air transport due to a lack of High Speed Rail, and the distance is large enough to discourage car driving. Several of the airports are on islands without road connection to the mainland.