We present a review of the life and scientific legacy of the founder of soil colloid chemistry Konstantin Gedroiz. The phenomenon of absorption was first studied in the mid-1800s, and Gedroiz started working on base exchange and absorption in soils in 1906. Based on the general pattern of cation exchange reactions, he proposed the concept of “absorption capacity” and “soil absorption complex”, developed ideas about exchange acidity and the rate of exchange reactions, revealed the unique role of absorbed sodium and potassium in soil processes, and proposed the theory of the accumulation of sodium due to exchange reactions. He was one of the first to classify soil on the basis of the absorbing complexes and cations, which was a new approach in pedology. He used the climate classification of soils, and described Podzols, Laterites, and Chernozems in terms of their absorbing complexes and cations. The system of classification worked for mature soils in which pedogenic processes had proceeded to such an extent that the profile characteristics reflected a climatic region, but was less effective in alluvial soils and eroded soils. His studies established the connections between chemical and physical processes and the morphology of soils. He studied the evolution of saline soils from a chemical point of view, which led to the practical recommendations for chemical reclamation of Solonetz and liming of acidic soils. Gedroiz’s work was groundbreaking but insufficiently known outside Russia until his books have been translated into English and German in the late 1920s. The soil microbiologist Selman Waksman in the 1925 translated 11 of his papers into English, and the United State Department of Agriculture distributed copies of these translations. In 1927 a textbook on chemical analysis, “Die chemische Bodenanalyse”, was published; in 1930 the books “Der adsorbierende Bodenkomplex und die adsorbierten Bodenkationen als Grundlage der genetischen Bodenklassification” and “On the Problem of exchangeable Hydrogen and exchangeable Aluminium in acid soils”, a 1931 – “Die Lehre vom Adsorptionsvermögen der Böden”.