The 8x10 black-and-white image of Hopper was lifted from a Highland Park, Los Angeles gallery on Saturday during an art show, reports People.
Lee is offering a $25,000 (£15,520) reward for the picture's return. He took the photo himself with a Polaroid camera.
The My Name is Earl star is said to be devastated following the theft.
He is asking anyone with information about the photo to contact the THIS Los Angeles art collective.