Cycloteuthis is a genus of squid in the family Cycloteuthidae. It is distinguished from the genus Discoteuthis by the presence of a tail on the mantle. The species C. akimushkini is currently considered a junior synonym of C. sirventi, however this is inconclusive and the World Register of Marine Species has C. akimushkini as a valid species.

The genus contains bioluminescent species.

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