We have developed a high‐yielding synthesis of meso‐tetraalkylporphyrins, which previously have been obtained only in lower yields. By employing MontmorriloniteK10 as the acid catalyst and 3Åmolecularsieves as the dehydrating agent, yields that reached 70 % could be achieved with some aliphatic aldehydes. The free‐base porphyrins with decyl (C10) or longer chains were imaged at the single‐molecule