Tomcat may refer to:
- A male cat, known as a tom or tommiecat
 - Tomcats (film), a 2001 comedy film
 - Apache Tomcat, an open-source Java Servlet Container developed by the Apache Software Foundation
 - Beretta Tomcat, a small .32 caliber pistol
 - F-14 Tomcat, a military jet fighter used by the United States Navy from 1974 to 2006
 - TomKat, a portmanteau for celebrity couple Tom Cruise & Katie Holmes
 - Tom Cat, a character from the animated series Tom and Jerry
 - Tom Cat (band), a Japanese band who contributed to the Fist of the North Star soundtrack
 - TOMCAT/SLIMCAT, a chemical transport model
 - The Tomcats, Brian Setzer's first rockabilly music group
 - Tomcat (video game), a 1989 computer game published in the UK by Players Software
 - Waspair HM 81 Tomcat, ultralight aircraft
 - Rove beetle, also known as Tomcat in Indonesia.