We evaluated the effects of commercially available fatty acid (FA) supplements enriched with palmitic (C16:0) or stearic acid (C18:0) on nutrient digestibility and production responses of dairy cows. Thirty-six multiparous Holstein cows (146 ± 84 DIM) were used in a truncated Latin square arrangement of treatments with 2 consecutive 35-d periods, with the final 5 d used for sample and data collection. Treatments were (1) control (CON; diet containing no supplemental FA); (2) C16:0-supplement (PA; 84% C16:0, 4% C18:0, 9% C18:1); and (3) C16:0 and C18:0-supplement (SA; 33% C16:0, 53% C18:0, 5% C18:1). Supplements were fed at 1.5% DM and replaced soyhulls in CON. The statistical model included the random effect of cow nested within square and the fixed effects of treatment, period, square, and their interactions. Contrasts were (1) overall effect of FA treatments [CON vs. FAT; 1/2 (PA + SA)]; and (2) effect of FA supplement (PA vs. SA). Results are presented in the following sequence: CON, PA, SA. There were no effects of treatments on DMI, BW, or BW change. Compared with CON, FAT treatments decreased total FA (76.7, 76.3, 67.6%, P < 0.01), 16-carbon FA (74.3, 69.0, 68.0%, P < 0.01), and 18-carbon FA (78.3, 82.1, 67.2%, P < 0.01) digestibility. Compared with SA, PA increased DM and NDF digestibility by 3.6 and 4.8% units, respectively (P < 0.01). PA also increased total FA and 18-carbon FA digestibility (P < 0.01) but did not alter 16-carbon FA digestibility (P = 0.55). Using a Lucas test, apparent digestibility coefficients were 0.73 and 0.62 for the PA and SA supplements, respectively. Compared with CON, FAT increased milk yield (43.1, 45.7, 44.8 kg/d, P = 0.01), tended to increase ECM (44.8, 46.4, 44.5 kg/d, P = 0.08), but did not affect yield of milk fat (1.55, 1.65, 1.52 kg/d P = 0.19) or milk protein (1.43, 1.44, 1.46 kg/d, P = 0.32). Compared with SA, PA increased ECM (P = 0.03) and milk fat yield, (P < 0.01) but had no effect on milk protein yield (P = 0.47). Our results indicate that high producing dairy cows respond better to a FA supplement enriched in C16:0 compared with a supplement enriched in C18:0, which is likely due in part to PA increasing FA and NDF digestibility compared with SA.