In 2018, Lego introduced a new Power Functions system, known as Powered Up, or Power Functions 2.0. This system was brought to replace the old Power Functions brought about in 2007. This system was introduced with the Passenger Train (set number: 60197) and the Cargo Train (set number: 60198). In 2019, the Disney Train was released, with the motorised elements in the tender. In 2020, the Lego Crocodile Locomotive was released, designed to be motorised with Powered Up Large Motor, not the usual train motor. In June 2022 LEGO introduced the Express Passenger Train (set number: 60337) and Cargo Train (set number: 60336), also powered by Powered Up, which features the ability of the train to be controlled via Bluetooth and a smartphone app.


Lego Trains (stylized as LEGO Trains) is a product range and theme of the construction toy Lego, which incorporates buildable train sets. The Lego Trains theme became a sub-theme of Lego City in 2006. Products in the range have included locomotives, tracks, rolling stock, stations, signal boxes, and other track-side buildings and accessories. The theme is popular among adult fans, as well as children, and has spawned international associations and conventions. The train system is sometimes referred to as 'L-gauge' among Lego fans, in reference to traditional model railway scales. Lego trains use a nominal gauge of 37.5 mm (1+15⁄32 in), based on 5-stud track centerlines gauge, corresponding with a circa 1:38 scale.

Lego trains are popular among adult fans of Lego, and Lego Train clubs around the world.

A number of these Lego train clubs exhibit large model train layouts at various community functions, train shows, and Lego conventions, such as BrickFest. Some of the largest layouts in the United States have been the result of ILTCO's (International Lego Train Club Organization) lead combined efforts by several train clubs at the 2005, 2006, and 2007 National Model Railroad Association national conventions. Lego has also introduced train sets designed by members of the Lego community, for example, Santa Fe set by James Mathis, and the Train Factory set in March 2007.

The community was also supported by a magazine about Lego trains called Railbricks, created by Jeramy Spurgeon and written by Lego train fans from around the world. Railbricks is no longer active.

A computer program called Track designer was created by Matt Bates to help fans plan track layouts. This program is no longer supported, but was the inspiration for similar programs such as TrackDraw by Cary Clark (no longer supported), and BlueBrick by Alban Nanty which is still supported at the time of writing.

In late December 2016, prominent train builder Cale Leiphart along with several others created Brick Model Railroader (BMR), which was created to replace Railbricks as a hub of the train building community. Brick Model Railroader is a news and blog site with the intention of spreading insightful ideas and techniques to all fans of Lego trains. They also now offer 'Premium Instruction Kits', which are instructions for train models, from their store.