Edmonton police are appealing for help to locate a mother and her five-month-old son, who have not been seen since July 16. 26-year-old Kirsty McDonald and her son were last seen in Butler Street, Kuranda about 30 kilometres north-west of Cairns at 6.30pm.

They were driving a grey Mazda 6 with Queensland registration 463 LYM and police hold concerns for their safety as Ms McDonald has not been in contact with family, which is out of character.

She is described as Caucasian, approximately 155cms tall with a slim build and dark brown hair.

Anyone who may have seen Ms McDonald or her son is urged to contact Crime Stoppers on 1800 333 000