Susan "Sue" Sylvester is a fictional character of the Fox musical comedy-drama series, Glee. The character is portrayed by actress Jane Lynch, and has appeared in Glee from its pilot episode, first broadcast on May 19, 2009. Sue was developed by Glee creators Ryan Murphy, Brad Falchuk, and Ian Brennan. For the show's first four seasons, Sue is the coach of the William McKinley High School cheerleading squad, and a ruthless bully to both students and faculty members alike who wears track suits. Because her cheerleading squad competes with the glee club for the school's limited funding, she is often at odds with the club and more particularly its director Will Schuester (Matthew Morrison). Sue is the main antagonist throughout the series' run. In the show's fifth season, Sue is made the school's new principal.

Due to Lynch's initial limited availability, Sue was originally set to be a recurring character while Lynch was working on a Damon Wayans pilot for the American Broadcasting Company (ABC). When that pilot fell through, Sue became a starring role. The character has been acclaimed by critics. Mary McNamara for the Los Angeles Times has written that "Lynch alone makes Glee worth watching", while Entertainment Weekly's Ken Tucker has called Sue "the greatest Broadway-musical villain to ever co-star in a TV series". In recognition of her portrayal of Sue, Lynch won an Emmy and a Golden Globe Award.