Mexican Train, also known as simply Trains, is a game played with dominoes. The object of the game is for a player to play all the dominoes from his or her hand onto one or more chains, or "trains", emanating from a central hub or "station". The game's most popular name comes from a special optional train that belongs to all players. However, the game can be played without the Mexican Train; such variants are generally called "Private Trains" or "Domino Trains". It is related to the game Chicken Foot.

The object of all Trains games is to be the first player to place all of their dominoes. Dominoes may be placed onto the player's train, onto the Mexican train if available, or on the trains of other players under special circumstances.

The game is generally played with 2 to 8 players, though a large enough domino set can support 16 players or more. A double-six set can be used by up to four players, but the following extended sets are generally recommended to allow a substantial starting hand and boneyard: