A high-frequency signal line includes a dielectric body including flexible dielectric sheets laminated in a direction of lamination and also including a first line portion, a second line portion extending along the first line portion, and a third line portion connecting ends in a specified direction of the first and second line portions. In the dielectric body, a signal line extends through the first, second and third line portions, and a first ground conductor and a second ground conductor face the signal line from both sides in the direction of lamination. One or more interlayer connection conductors are pierced in the dielectric sheets to connect the first ground conductor and the second ground conductor. None of the interlayer connection conductors is provided in a portion of the third line portion that is farther in a direction opposite to the specified direction than the signal line when viewed from the direction of lamination.