TCT is a TLA that can mean:

• Teenage Cancer Trust
• Texas City Terminal Railway
• thrombin clotting time, a test used in blood coagulation.
• Tri-State Christian Television, a 24-hour Christian cable television network broadcasting to 15 U.S. States and Canada. (Was formerly known as Total Christian Television)
• tungsten carbide tipped, generally when describing blades and saws used for woodworking or more commonly metalworking.