Fatty acid (FA) supplements based on palmitic acid (PA) and stearic acid (SA) are commonly used to increase dietary energy density for lactating dairy cows. There is limited literature directly comparing supplements enriched in PA and SA to a blend of these FA. Our hypothesis was that PA would increase milk fat and decrease intake while SA would have no effect on intake. Treatments were (1) Control (CON; no additional fat), (2) high palmitic supplement (HP; 90.7% C16:0, 2.4% C18:0, and 5.8% cis-9 C18:1), (3) high stearic supplement (HS; 1.7% C16:0, 90.5% C18:0, and 5.9% cis-9 C18:1), and (4) a blend of PA and SA (INT; 45.7% C16:0, 46.4% C18:0, and 5.7% cis-9 C18:1). Twelve multiparous, post-peak (138.5 ± 21.0 DIM) Holstein cows were arranged in a 4 × 4 Latin square design with 21-d periods. Samples were collected the last 3 d of each period. The statistical model included the random effect of cow and period and the fixed effect of treatment. There were no differences between treatments for DMI (25.03 ± 2.29 kg), milk yield (39.19 ± 7.31 kg), milk protein concentration and yield, or MUN. Milk fat percent was increased 0.44 and 0.14 percentage points by HP compared with CON and SA, respectively (P = 0.03). Milk fat yield was increased by 110 g/d by HP and 140 g/d by INT compared with CON (P < 0.01). Although HP increased milk fat concentration 0.34 percentage points compared with INT, fat yield did not differ. Milk fat concentration and yield were not different between CON and SA. As expected, HP and INT increased C16 FA in milk fat and decreased both de novo and preformed FA. Preformed FA concentration was the highest in SA (both P < 0.0001). There was a trend for HP to decrease de novo FA yield (P = 0.09). The INT treatment increased preformed FA yield 60.5 and 50.4 g/d compared with CON and HP (P = 0.02). The HP and INT treatment increased yield of C16 FA 154.1 and 90 g/d compared with CON, respectively. On the basis of fat yield, the 2 supplements that had greater amounts of PA had a greater response.