A novel class of luminescent trinuclear alkynylgold­(I) complexes with N-alkyl substituted triindole ligands has been synthesized and characterized. They are found to exhibit rich photophysical and electrochemical properties. The complexes have been demonstrated to display interesting supramolecular assembly with spherical nanostructures in aqueous THF solution through a cooperative growth mechanism. The self-assembly process is shown to be mediated by the π–π stacking interactions and hydrophobic–hydrophobic interactions of the triindole moieties upon solvent modulation. These gold­(I) complexes have been employed as active materials in the fabrication of solution-processable resistive memory devices, showing promising binary memory performances with low switching threshold voltages of ca. 1.5 V, high ON/OFF current ratio of up to 105, long retention time of over 104 s, and excellent stability. The present work opens up a new avenue for the future design of versatile organogold­(I) complexes that could serve as multifunctional materials.