Master=Dik is the second EP by American alternative rock band Sonic Youth. It was released on November 4, 1987 by record label SST.

Inspired by New York City hip hop from the late 1980s, the song used a drum machine, sampled Kiss and name dropped Ciccone Youth, a Sonic Youth side project that would release an album the following year. The B-sides comprised several interview snippets,; parody and/or cover songs that pay tribute to the Ramones, Jesus and Mary Chain and Beatles; plus short-form sound collages, field recordings, musique concrète and human beatboxing. Dinosaur Jr.’s J. Mascis plays guitar on „Beat on the Brat“.

Master=Dik’s liner notes reprint a rant by Ben Weasel from the November 1987 issue of the fanzine Maximumrocknroll. In the article, Weasel criticized Sonic Youth, Hüsker Dü and several other indie rock bands from the 1980s for eschewing punk rock for a boring classic rock sound. Etchings on the vinyl’s inner groove read „Ciccone death rock dream tinkle“ on one side, and „Humpy pumpy psychoacoustik frenzy“ on the other. When it was originally released, the album sleeve bore a sticker reading „Not as good as Atomizer, so don’t get your hopes up, cheese!“ The same sticker appeared on Big Black’s EP Headache released that same year, and referred to that band’s previous album.

All tracks written by Sonic Youth, except Beatles cover „Ticket to Ride“, written by John Lennon and Paul McCartney, and Ramones cover „Beat on the Brat“, written by Joey Ramone.