Notts Police were alerted to the matter at 11.10am after reports of the seven-year-old girl being seen in Worksop town centre.
It is understood she boarded a bus to Creswell where she was found half an hour later.
A Derbyshire Police spokesman said: “We were contacted at 11.40am by a concerned member of the public who had found a young girl in the Creswell area.”
“Enquiries were made to establish the identity of the girl and where she was from.”
“Officers established she went missing from Nottinghamshire and officers from Nottinghamshire Police collected the young girl.”