Tris or TRIS may refer to:

Chemicals

• Tris(hydroxymethyl) aminomethane, a biochemical buffer

• Tris(2-chloroethyl) phosphate, a flame retardant

• Tris(2,3-dibromopropyl) phosphate, a flame retardant

• TRIS (trisescaline, trescaline), a psychedelic-related compound

People

• Tris Speaker, a baseball player

• Tris Prior, a character in the Divergent book series and its film adaptations

Other uses

• TRIS online, a former bibliographic database created by U.S. Department of Transportation Research Information Services online

• TRIS, the ICAO type designator for the Britten-Norman Trislander

• TRIS (Technical Regulations Information System), EU information system on planned technical regulations