A balun includes first, second, and third terminals, first, second, and third inductors, and a capacitor. The first and second inductors are electrically connected in series with each other between the first terminal and a ground point. The capacitor is electrically connected in series with the first inductor between the first terminal and the ground point. The capacitor is electrically connected in parallel with the second inductor between the first inductor and the ground point. The third inductor is electrically connected between the second terminal and the third terminal. The third inductor is magnetically coupled with at least the first inductor.