Officers were called to Wingfield Avenue and Southdene in Worksop at around 2.50am this morning (Saturday, June 26) after the fires were seen by a member of the public.
Pictures sent into the Worksop Guardian show one of the cars alight and the destruction caused to two vehicles after the fires were extinguished.
No-one was injured in the fires.
Nottinghamshire Police has stressed how dangerous fires are and appealed to anyone who may have seen or heard something to come forward.
Detective Inspector Stu Temple, of Nottinghamshire Police, said: “While no-one was injured in this incident, fire is incredibly destructive and can very quickly spread.
“It has the potential to cause catastrophic damage. Whoever did this was putting the local community ask risk and it is totally unacceptable.
“We are investigating this matter thoroughly and are working hard to establish what happened.
“I am now appealing for anyone who may have seen or heard something suspicious in the area at the time to come forward as a matter of urgency.
“Any information you have, no matter how insignificant you think it may be, could help us find who did this.”
Anyone with any information on the incident should contact Nottinghamshire Police on 101 quoting incident number 85 of June 26 2021.