Diamondoids are diamond-like hydrocarbon cage molecules that have emerged as promising candidates in a wide range of applications. Their inherent properties and availability for selective functionalization allows for a development of variously applicable scaffolds. However, the tendency of smaller diamondoid derivatives to sublimate at even slightly elevated temperatures coupled with solubility issues of larger derivatives offers a challenge for their preparation. Here, we present the first mechanochemical synthesis of several diamondoid ethers differing in the size and number of their cage subunits. Efficient mechanochemical preparation of such ethers is enabled solely by high-temperature ball milling conditions and does not proceed under ambient conditions. When compared to the conventional synthesis of the same ether derivatives, the calculated green chemistry metrics showed significant sustainability benefits of the mechanochemical approach. Thus, mechanochemical procedures are faster, allow for the use of an inorganic green base, result in comparable or superior reaction yields, and are overall more sustainable and eco-friendlier. Furthermore, application of mechanochemistry in the preparation of large diamondoid composites opens up a sustainable approach to the synthesis of next-generation materials consisting of diamondoid subunits, unhampered with solubility capabilities of the reactants.