Ideally, a sustainable chemical synthesis should involve the use of non‐toxic solvents and reactants, easy separations and purification by energy‐efficient processes. In this context, reconsidering the synthesis of widely used drugs is especially timely and should allow important benefits to be obtained in terms of environmental impact. Sulfonamides are pertinent as their synthesis generally requires the use of toxic and/or hard‐to‐remove solvents such as dichloromethane, DMF and DMSO. In addition, toxic and highly reactive sulfur‐containing sources such as sulfonyl chloride are often involved and coupled with amines. Moreover, the latter may exhibit some toxicity and are generally difficult to purify. Herein, we disclose the unprecedented and sustainable synthesis of sulfonamides by using sodium sulfinate as a commercial and stable sulfur source and nitroarenes as the nitrogen‐containing reactant. In addition, under the optimized conditions only water is used as a “green” solvent and the products are collected by simple filtration.