A circuit board and a circuit module more accurately provide impedance matching between an antenna coil and an electronic component electrically connected to the antenna coil, and include a board body including board portions and a plurality of laminated insulating material layers made of a flexible material. An antenna coil includes coil conductors provided in the board portion. Wiring conductors are provided in the board portion and electrically connected to the antenna coil. The board portion has a structure that is less likely to deform than the board portion. An integrated circuit electrically connected to the wiring conductors is mounted on the board portion.