The new linear molecule Ag‒C≡C‒Cl has been detected and fully characterized by means of rotational spectroscopy. It was synthesized by laser ablation of a silver rod in the presence of a gaseous sample containing a low concentration of CCl4 in argon, cooled to a rotational temperature approaching 2 K through supersonic expansion and analysed by chirped-pulse, Fourier transform microwave spectroscopy. Six isotopologues were investigated and for each the spectroscopic constants B0, DJ and X_aa ((_^35)"Cl)" were determined. The B0 values were interpreted to give the following bond lengths: r(Ag‒C) = 2.015(1) Å and r(C‒Cl) = 1.636(2) Å, with r(C≡C) = 1.2219 Å assumed from an ab initio calculation at the CCSD(T)/aug-cc-pV5Z level of theory. The Cu analogue Cu‒C≡C‒Cl was similarly identified and characterized.