A directional coupler includes first to fourth terminals, a first line, a second line, a ground conductor portion, and a stack. The first line includes a first center portion, a first connecting portion, and a second connecting portion. The second line includes a second center portion, a third connecting portion, and a fourth connecting portion. A distance between the first and third connecting portions and a distance between the second and fourth connecting portions decrease toward the first and second center portions. The first to fourth terminals are located on a bottom surface of the stack.