Train of thought, also known as stream of thought, chain of thought or stream of consciousness is thinking in words. It also refers to the semi-constant internal monologue one has with oneself at a conscious or semi-conscious level.

Train of Thought is a hip hop album by East Coast rapper Talib Kweli & DJ Hi-Tek (collectively known as Reflection Eternal), released on October 17, 2000 (see 2000 in music) on Rawkus Records. Due to a series of underground hits in the late 1990s, both Kweli and Hi-Tek were hyped in the hip hop music media, and Train of Thought was a critical success, though sales were slim. Kweli's reflections on modern African-American culture, including criticisms of commercialism and violence like "these cats drink champagne/To toast death and pain/Like slaves on the ship talkin' 'bout who got the flyest chains".

"Train of Thought" was the third Single by a-ha released off of the Hunting High and Low album.