Cyclobarbital, cyclobarbitol or cyclobarbitone refers to a barbiturate derivative developed in the early 1970s in the Soviet Union.

It was available in Russia until 2019, marketed and distributed as Reladorm, a fixed-dose combination pairing 100 mg cyclobarbital and 10 mg diazepam (a benzodiazepine anxiolytic, muscle relaxant, and anticonvulsant) indicated for treating insomnia before it was discontinued in 2019.