O Gauge Diesel Locomotives

Shop O Gauge diesel locomotives for sale, from compact switchers and streamlined cab units to road diesels, passenger power, and modern mainline freight engines. Trainz carries new and pre-owned O Gauge diesels along with Postwar, MPC-era, vintage, discontinued, collectible, new old stock, estate-find, and hard-to-find locomotives as inventory becomes available.

Whether you're building a freight roster, matching a favorite railroad, assembling a multi-unit diesel consist, or replacing an engine from an earlier layout, browse Lionel diesels by era or explore dedicated O Gauge diesel collections from other major manufacturers.

Shop Lionel O Gauge Diesel Locomotives

Browse all Lionel O Gauge diesel locomotives or narrow your search to classic Postwar and MPC-era power.

Lionel Diesels All Lionel O Gauge Lionel Postwar Diesels Classic Postwar Lionel Lionel MPC Diesels MPC-era Lionel power

Other O Gauge Diesel Manufacturers

Shop dedicated O Gauge diesel locomotive collections from Atlas O, K-Line, MTH, and Williams.

Atlas O Atlas O diesel locomotives K-Line K-Line O Gauge diesels MTH MTH O Gauge diesels Williams Williams O Gauge diesels

O Gauge diesels cover a wide range of prototype styles, including yard switchers, road switchers, streamlined cab units, passenger diesels, and modern high-horsepower freight locomotives. Popular families include F units, GP and SD series locomotives, Alco diesels, switchers, and large modern road engines.

Road name is often just as important as locomotive type. Depending on current inventory, shoppers may find O Gauge diesel engines lettered for Santa Fe, Union Pacific, Pennsylvania Railroad, New York Central, Norfolk Southern, CSX, BNSF, Conrail, and many other historic and modern railroads.

Many O Gauge diesel locomotives are available as coordinated multi-unit sets, particularly streamlined cab units and passenger diesels. These combinations recreate the appearance of prototype diesel consists while allowing manufacturers to offer powered and non-powered units in different configurations.

• A Unit: a cab-equipped diesel locomotive with the operating cab at the front.
• B Unit: a cabless booster intended to operate behind or between cab-equipped units.
• A-B Set: one A unit paired with one B unit.
• A-B-A Set: two cab-equipped A units with a B unit between them.
• A-B-B-A Set: two A units and two B units creating a four-unit diesel consist.
• Powered and Dummy Units: some sets combine powered locomotives with non-powered units to create a longer prototype-style consist.

Depending on inventory, Trainz may offer individual powered and dummy units as well as matching A-B, A-B-A, and larger diesel locomotive sets.

O Gauge diesel locomotives span many generations of model train technology. Older engines may use straightforward conventional control, while newer locomotives can include digital command systems, sound, lighting, remote couplers, smoke effects, and other operating features.

Lionel locomotives may use conventional control, TMCC, Legacy, or other Lionel systems depending on the model and production period. MTH locomotives may use conventional operation or DCS-compatible electronics. Always review the individual listing for the exact control system and features before purchasing.

The pre-owned market is an important part of O Gauge diesel collecting. Trainz inventory may include Postwar locomotives, MPC-era engines, discontinued modern releases, new old stock, estate finds, collectible road names, individual powered or dummy units, and models no longer available through current manufacturer catalogs.

When shopping a pre-owned diesel locomotive, review the listing for condition, testing information, control system, sound, lighting, smoke features where applicable, couplers, original packaging, and included components.

Trainz purchases qualifying O Gauge model train collections that may include diesel locomotives, steam engines, freight and passenger cars, train sets, track, transformers, accessories, parts, and other three-rail equipment.

Whether you're downsizing a collection or helping with an estate, visit Sell My Trains – How It Works to learn more about selling your O Gauge trains to Trainz.

What types of O Gauge diesel locomotives are available?

Common types include switchers, road switchers, cab units, passenger diesels, four-axle and six-axle freight locomotives, powered and dummy units, and multi-unit diesel sets.

What is the difference between an A unit and a B unit?

An A unit has a cab, while a B unit is a cabless booster intended to operate with one or more cab-equipped units. They are commonly seen together in A-B and A-B-A diesel consists.

Do O Gauge diesel locomotives have sound and command control?

Many modern models do. Features can include sound, lighting, smoke, remote couplers, TMCC, Legacy, DCS, or other command-control systems depending on the manufacturer and specific locomotive.

Can Lionel and MTH diesel locomotives run on the same layout?

Many Lionel and MTH O Gauge locomotives can operate on the same compatible three-rail track using conventional control, but their advanced command features may require different control systems. Check the specifications of each locomotive and controller.

Does Trainz sell used O Gauge diesel locomotives?

Yes. Depending on current inventory, Trainz may offer pre-owned, Postwar, MPC-era, vintage, discontinued, collectible, new old stock, estate-find, and hard-to-find O Gauge diesel locomotives.