An ignition coil for an internal combustion engine has a primary coil and a secondary coil, a case, a high voltage connection terminal, and a conduction terminal. The high voltage connection terminal is accommodated in the case in a state being sealed by a filling resin. The high voltage connection terminal is disposed in a state inclined an aligned direction of the secondary coil and the conduction terminal, and is configured to be elastically deformable. The conduction terminal includes an engaging part for engaging a terminal distal end portion of the high voltage connection terminal and a supporting part for supporting a terminal intermediate portion of the high voltage connection terminal which is a portion closer to a connecting portion with the secondary coil than the terminal distal end portion is. In the aligned direction, the terminal distal end portion contacts with the engaging part from a side opposite to a secondary coil side, and the terminal intermediate portion contacts with the supporting part from the secondary coil side.