These proceedings highlight a selection of recent ATLAS and CMS measurements which target either the production of a single top quark or the associated production of a top-antitop quark pair together with a $W$ boson, a $Z$ boson, or a photon ($\gamma$). The highlighted analyses are based predominantly on proton-proton collision data collected by the two experiments during Run 2 of the LHC at a centre-of-mass energy of $\sqrt{s}=13$ TeV with datasets corresponding to integrated luminosities of up to 77.5 fb$^{-1}$. One combination of ATLAS and CMS single top quark measurements employing the full Run 1 dataset based on $\sqrt{s}=7,8$ TeV is also included. Such measurements probe the Standard Model couplings of top quarks to gauge bosons and offer sensitivity to a number of anomalous non-Standard-Model effects.