This paper reports liquid heat capacity data on members of the linear saturated dicarboxylic acid family and one dicarboxylic acid derivative measured using modulated differential scanning calorimetry. The dicarboxylic acids range in carbon number from 4 to 14. The compounds studied are dimethyl oxalate (CAS RN 553-90-2), adipic acid (1,6-hexanedioic acid, CAS RN 124-04-9), pimelic acid (1,7-heptanedioic acid, CAS RN 111-16-0), suberic acid (1,8-octanedioic acid, CAS RN 505-48-6), azelaic acid (1,9-nonanedioic acid, CAS RN 123-99-9), sebacic acid (1,10-decanedioic acid, CAS RN 111-20-6), dodecanedioic acid (1,12-dodecanedioc acid, CAS RN 693-23-2), and tetradecanedioic acid (1,14-tetradecandioic acid, CAS RN 821-38-5). The experimental results show a consistent family trend and are compared to prediction methods and data from other chemical families. A discussion of the differences in liquid heat capacity between carboxylic acids, n-alkanes, and dicarboxylic acids is presented, the accuracy of prediction through thermodynamic equations is analyzed for the family, and a correction factor for the Ruzicka–Domalski prediction method (Růžička, V. R., Jr.; Domalski, E. S. Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature using Group Additivity. II. Compounds of Carbon, Hydrogen, Halogens, Nitrogen, Oxygen, and Sulfur. J. Phys. Chem. Ref. Data 1993, 22, 619–657.) for dicarboxylic acids is given.