环己二烯可能指：

• 1,3-环己二烯
• 1,4-环己二烯

• 苯或它的理论异构体1,3,5-环己三烯
• 环己烯

Cyclohexadiene may refer to:

• 1,3-Cyclohexadiene
• 1,4-Cyclohexadiene

• Benzene or its theoretical isomer 1,3,5-Cyclohexatriene
• Cyclohexene