Cwichelm ([ˈkwik.heɫm] QUICK-helm;[1] died c. 636) was an Anglo-Saxon king of the Gewisse, a people in the upper Thames area who later created the kingdom of Wessex.

Cynegils was also baptised at this time, by Bishop Birinus, with Oswald of Bernicia as his godfather.

The final entry in the Anglo-Saxon Chronicle concerning Cwichelm, in 648, states: "This year Cenwalh gave his relation Cuthred three thousand hides of land by Ashdown.

Kirby notes that the evidence is weak, confused, and shows signs of later changes to the record.

[7] The evidence that Cwichelm was king of the Gewisse is unassailable, but the question of his ancestry and relationship to Cynegils, if any, is much less certain.