The first examples of organic alloys of two room temperature liquids, obtained and characterized via in situ cryo-crystallography, are presented. Thiophenol and selenophenol, which exhibit isostructurality and similar modes of S⋯S and Se⋯Se homo-chalcogen interactions along with weak and rare S–H⋯S and Se–H⋯Se hydrogen bonds, are shown to form solid solutions exhibiting Veggard's law-like trends.