Effects of feeding diets containing fat supplements differing in saturation on milk production and energy partitioning were evaluated. Holstein cows (n = 32; 93 ± 35 DIM) were randomly assigned to treatment sequence in a crossover design experiment. Treatments were diets containing a saturated fat supplement (2.5% DM palmitic acid-enriched triglyceride [BergaFat T-300], SF) or an unsaturated fat supplement (2.5% DM soybean oil, UF). Diets utilized corn silage and alfalfa silage as forage sources and contained 25% NDF, 18% forage NDF, 32% starch, 18% CP, and 4.6% FA. Treatment periods were 28 d in length with the final 5 d used for sample and data collection. The statistical model included the random effect of cow and fixed effects of treatment and period. Compared with UF, SF increased milk fat concentration (3.07% vs. 2.42%; P < 0.01) and yield (1.35 vs. 1.11 kg/d; P < 0.01), but reduced milk protein concentration (3.05% vs. 3.12%; P < 0.01) and yield (1.40 vs. 1.44 kg/d; P < 0.05). Treatment did not alter milk yield (46 kg/d; P = 0.6), but SF did increase FCM (41.9 vs. 38.1 kg/d; P < 0.01) and ECM (42.6 vs. 39.8 kg/d; P < 0.01) compared with UF. DMI and energy intake did not differ between treatments and averaged 25 kg/d and 41.2 Mcal/d, respectively (both P > 0.6). However, SF increased the milk to feed ratio (ECM/DMI) compared with UF (1.67 vs. 1.53; P < 0.01). Compared with UF, SF reduced BW gain (5.2 vs. 12.8 kg/28 d; P < 0.05) but did not alter BCS (P = 0.8) or fat thickness over the rump (P = 0.7) and rib (P = 0.5). SF decreased plasma concentration of insulin (1.18 vs. 1.34 μg/L, P < 0.05), NEFA (122 vs. 137 μEq/L, P < 0.01), and triglycerides (7.9 vs. 8.5 mg/dL, P = 0.05) compared with UF. There was no effect of treatment on plasma concentration of glucose (P = 0.3). Compared with UF, SF increased milk energy as a fraction of NE_L use (71 vs. 66%, P < 0.01) and reduced calculated body energy gain as a fraction of NE_L use (3 vs. 8%, P < 0.01). In conclusion, the 2 diets resulted in similar NE_L intake but the SF diet containing the palmitic acid-enriched triglyceride increased milk fat yield and partitioned more energy toward milk, while the UF diet containing soybean oil reduced milk fat yield and partitioned more energy toward body gain.