SYN

Syn or SYN may refer to:

In music

 * The Syn, a band
 * Synyster Gates, lead guitarist of the band Avenged Sevenfold

Fictional characters

 * Doctor Syn, in novels by Russell Thorndike

Other uses in arts and entertainment

 * SYN Media, a youth media organization based in Melbourne, Australia

In science and technology

 * Syn addition, in organic chemistry
 * Syn conformation in alkane stereochemistry
 * Syndal railway station, Melbourne
 * Synonym (taxonomy), a system of accepted alternative names for species
 * SYN (TCP), synchronise packet in transmission control protocol (TCP)
 * Synchronous idle (␖), one of the C0 and C1 control codes
 * SYN (OSC), a standardized namespace within Open Sound Control

Other uses

 * Syn (goddess), in Norse mythology
 * Coalition of Left, of Movements and Ecology (Synaspismós, abbreviated SYN or ΣΥΝ), a Greek political party