"Yesterday, When I Was Mad" is a song by English synth-pop duo Pet Shop Boys, released as the fifth and final single from their fifth studio album, Very (1993), on 29 August 1994 by Parlophone. The single, both written and produced by Neil Tennant and Chris Lowe, peaked at number 13 on the UK Singles Chart and number four on the US Billboard Hot Dance Club Play chart. The song was remixed by Jam & Spoon for its single release, among other things removing a compression effect applied to Tennant's voice during the verses. Its music video was directed by Howard Greenhalgh. One of the B-sides is a cover of the Noël Coward song "If Love Were All".

The Pet Shop Boys are a British synth-pop duo formed in London in 1981. Consisting of primary vocalist Neil Tennant and keyboardist Chris Lowe, they have sold more than 50 million records worldwide, and were listed as the most successful duo in UK music history in the 1999 edition of The Guinness Book of Records.