Staff at the Netherfield branch made the discovery on Sunday as they were unloading fruit at the supermarket.
They seemed to be pretty taken with the small amphibian and affectionately named it Lloyd.
A Lidl spokesperson said: “Our team were slightly surprised to spot this little frog hiding in our store warehouse and immediately contacted the RSPCA to ensure that it could be put into safe hands.
“Our quality assurance team are now looking into the matter with the supplier, to understand how he/she could have made such a long journey.”
There are over 800 species of tree frogs, but not all of them live in trees and they can vary in size, ranging from between just 2.5cm (less than an inch) to 12.7cm (5in).
Animal collection officer at the RSPCA, Hayley Day, was sent to collect the creature. She said: “The little tree frog was sat on top of some of bananas which staff had started to unload and put on the shelves.
“I managed to get him inside a box with wet tissue paper inside to keep him moist. He must have also had quite the shock when he emerged in a Nottinghamshire supermarket considering he’s used to more tropical climates usually!”
Lloyd was taken to a specialist keeper who will now look after him.