Look up third rail or live rail in Wiktionary, the free dictionary.

A third rail is an extra rail used for supplying electricity to trains.

Third rail may also refer to:

• Third rail (model railroading), in rail transport modelling, a technique that is sometimes applied in order to facilitate easier wiring
• The extra rail on a dual gauge railway
• "Third Rail" (song), a 1993 song by Squeeze
• Third rail of politics, a political metaphor
• The Third Rail, an online magazine about transportation
• The Third Rail (band), an American pop group
• Emergency Third Rail Power Trip, an album by Rain Parade
• Third Rail (TV series), a Singaporean TV drama series
• Third Rail (MLS supporters association), an independent supporters' group for New York City FC
• Third Rail Releasing, a distribution banner of The Weinstein Company
• The Third Rail (album), a 1996 album by New York City-based blues rock band Railroad Jerk
• A Guard rail (rail), used to prevent a train from derailing.