The invention relates to a filling device for oil level regulation on oil pans in engines and transmissions, with an opening 1 in the base of the oil pan 2 which is closable with an oil drain screw 10, an oil filling collar 3 being arranged over the opening 1, the oil filling collar 3 projecting into the interior 4 of the oil pan, and a filling pipe 5 as an extension of the oil filling collar 3 being releasably attached to the oil filling collar 3, the free end 6 of the filling pipe 5 representing an overflow opening 7; the invention also relates to an oil pan containing the inventive filling device.