Cellulose, a natural polymer material with abundant natural sources, is non-toxic, renewable, and biodegradable, making it one of the most promising green materials. Its inherent hydrophilicity dramatically limits the development and application of cellulose products. Hydrophobic modification can significantly change cellulose properties and endow it with additional functions depending on the types of modifying molecules. Controlled modification of cellulose by long-chain hydrophobic molecules is challenging. Significant advances took advantage of new reaction systems and copolymerization. This paper reviews recent innovations in long-chain cellulose hydrophobic modification. A brief value-adding assessment provides a reference for green changes of cellulose to make it fit for future applications.