Redox properties of a series of azolium salts, including benzothiazolium, thiazolinium, thiazolium, triazolium, imidazolium, and imidazolinium salts, have been systematically investigated. The series includes a broad range of N-arylthiazolium salts that collectively demonstrate the ability to fine-tune the reduction potential of the thiazolium ring via electronic modification of the N-aryl moiety. Additionally, a novel class of N-arylthiazolinium salts has been synthesized and characterized. In contrast to what has been observed for imidazolium and imidazolinium counterparts, saturation of the thiazolium backbone to give thiazolinium salts results in a more facile electrochemical reduction.