A chip package is provided. A first bonding structure is disposed on a first redistribution layer (RDL). A first chip includes a sensing region and a conductive pad that are adjacent to an active surface. The first chip is bonded onto the first RDL through the first bonding structure. The first bonding structure is disposed between the conductive pad and the first RDL. A molding layer covers the first RDL and surrounds the first chip. A second RDL is disposed on the molding layer and the first chip and is electrically connected to the first RDL. A second chip is stacked on a non-active surface of the first chip and is electrically connected to the first chip through the second RDL, the first RDL, and the first bonding structure. A method of forming the chip package is also provided.