The Theme of Cherson (Greek: θέμα Χερσῶνος, Thema Chersōnos), originally and formally called the Klimata (Greek: τὰ Κλίματα), was a Byzantine theme (a military-civilian province) located in the southern Crimea, headquartered at Cherson.

Byzantine authority was re-established by Emperor Theophilos (r. 829–842), who displayed interest in the northern littoral of the Black Sea and especially his relations with the Khazars.

Its weakness is underlined by the stipulation, in the Byzantine treaties with the Rus' of 945 and 971, of the latter's undertaking to defend it against the Volga Bulgars.

At the same time, possibly after the defeat of Georgius Tzul in 1016, the theme was extended over the eastern Crimea as well, as evidenced by the styling of a certain Leo Aliates as "strategos of Cherson and Sougdaia" in 1059.

[8] The cities of the theme, however, appear to have retained considerable autonomy in their own government, as exemplified by Cherson itself, which was administered by the local magnates (archontes) under a proteuon ("the first").