Enthalpies of solution of glycine, L-alanine, L-serine, L-threonine, diglycine, and triglycine in aqueous solutions of D-sorbitol, D-mannitol, and xylitol have been measured by calorimetry at 298.15 K. These data have been used to calculate the transfer enthalpies of the amino acids and glycine peptides from water to aqueous solutions of sugar alcohol. It has been observed that all the values of the transfer enthalpies are negative and decrease with an increase of the concentration of sugar alcohol in the aqueous solutions. The results are discussed in terms of solute-solute and solute-solvent interactions. The primary interactions between the zwitterionic group of the amino acid molecule and the hydroxyl group of the sugar alcohol molecule exhibit exothermic effects and make negative contributions to the transfer enthalpies. The hydrophilic side chains in the solute molecules also enhance these negative contributions effectively.