Thujene (or α-thujene) is a natural organic compound classified as a monoterpene. It is found in the essential oils of a variety of plants, and contributes pungency to the flavor of some herbs such as Summer savory.

The term thujene usually refers to α-thujene. A less common chemically related double-bond isomer is known as β-thujene (or 2-thujene). Another double-bond isomer is known as sabinene.