In the present study, hemicelluloses were isolated from black poplar (Populus nigra L.) sawdust, which is generated by the wood industry in large quantities as lignocellulosic waste. The monosaccharide composition of hemicelluloses was determined by gas chromatography. Xylose was the predominant monosaccharide unit, at 81.13%. Isolated hemicelluloses were then esterified with octanoyl, decanoyl, and lauroyl chloride, and the produced derivatives were characterized in terms of percent yield, degree of substitution (DS), solubility, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Hemicellulose derivatives had DS values ranging from 0.83 to 0.97, and percent yields ranging from 61.54% to 62.31%. FTIR analysis confirmed esterification. TGA indicated that the hemicellulose derivatives offered lower thermal stabilities than native hemicelluloses. Solubility analysis indicated that esterification increased the hydrophobic capacity of hemicelluloses. Generally, the hemicellulose derivatives obtained could be used to make biodegradable and environmentally friendly plastics, resins, films, and coatings for industrial utilization.