FlatCam is a thin form-factor camera that consists of a coded mask placed on top of a bare, conventional sensor array. The design is inspired by coded aperture imaging principles; each sensor pixel records a linear combination of the scene in front of the camera, and a computational algorithm reconstructs the image. A key design feature of the FlatCam is its slim form-factor, which enables imaging using extremely thin, even flexible surfaces that operate over a wide spectral range and are amenable to monolithic fabrication. We demonstrate the potential of the FlatCam design using two prototypes: one at visible wavelengths and one at infrared wavelengths.