In this contribution we overview the recent developments in the use of the statistical associating fluid theory (SAFT) in the areas of electrolytes, interfaces, and polymers. The focus will be on representative examples of: the use of SAFT together with a Debye-Huckel (DH) and mean spherical approximation (MSA) treatment to examine the effect of added salt on the vapour-liquid equilibria (vapour pressure and density) of aqueous solutions of strong electrolytes; the incorporation of the SAFT free energy functional into a local density functional theory (DFT) to examine the vapour-liquid interface (interfacial thickness and surface tension) of associating fluids; and the use of SAFT with parameters obtained for the long-chain alkanes to describe the adsorption and co-adsorption of alkanes and alkenes in polyethylene polymers. Future directions in this area will also be discussed.