Lego Trains is a product range and theme of the construction toy Lego

Lego

Lego is a line of construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. The company's flagship product, Lego, consists of colorful interlocking plastic bricks and an accompanying array of gears, minifigures and various other parts...

, which incorporates buildable train set

Train set

A train set is a set, normally consisting of a model train and a small circle or oval of track. A set of rail tracks of more appropriate size for a train set is a model railroad layout...

s. Products in the range have included locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

s, tracks

Rail tracks

The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...

, rolling stock

Rolling stock

Rolling stock comprises all the vehicles that move on a railway. It usually includes both powered and unpowered vehicles, for example locomotives, railroad cars, coaches and wagons...

, train station

Train station

A train station, also called a railroad station or railway station and often shortened to just station,"Station" is commonly understood to mean "train station" unless otherwise qualified. This is evident from dictionary entries e.g...

s, signal houses

Signal box

On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable...

, and other track-side buildings. 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' amongst fans, in reference to traditional model railway scales

Rail transport modelling scales

Rail transport modelling utilises a variety of scales to ensure scale models look correct when placed next to each other. Model railway scales are standardized worldwide by many organizations and hobbyist groups...

.
The design of Lego trains has developed substantially, with several different systems introduced, with varying degrees of cross-compatibility.
Lego trains were first introduced in 1966 with Lego set number 080.