Kent fire crews were first called to the vehicle fires in the Buckland Road and Somerfield Road areas at 01:15 BST.
Within an hour, 15 fire engines were also sent to The Works bookshop in Week Street, where three floors were alight.
A 22-year-old from the town is being questioned over the fires which led to a number of residents being evacuated from their homes.
There were no reported casualties.
Kent Police said they were treating the cause of the fires as suspicious and were were not ruling out them being linked.
Week Street remains closed and fire crews are expected to remain at the scene for several days.
A man has been arrested after several fires in Maidstone town centre damaged four shops and five cars.