We present the predictions with standard sirens at gravitational-wave detectors, such as the Laser Interferometer Space Antenna (LISA) and the Einstein Telescope (ET), for interacting dark energy theories. We focus on four models characterized by couplings between the dark energy field and the dark matter fluid arising from conformal or disformal transformations of the metric, along with an exponential self-interacting potential. To this purpose we construct mock catalogs and perform a Markov chain Monte Carlo analysis by considering ET and LISA standard sirens, and also their combination with baryon acoustic oscillation (BAO) and supernovae Ia (SNIa) data. We find that in all four models considered, the accuracy on the parameter increases by 1 order of magnitude at when compared to the data set, possibly shedding light in the future on the origin of the tension. The combination of standard sirens with allows to improve the accuracy on some coupling and exponential parameters, hinting at future prospects for constraining interactions in the dark sector.