We investigated the effects of dietary fat supplementation (oilseed vs. no-oilseed) and type of oilseed (sunflower vs. canola) during late gestation on postpartum (pp) reproductive performance. Pregnant Holsteins were, blocked by BCS and parity, assigned to 1 of 3 diets containing 8% DM rolled sunflower (SUN; n = 45) or canola seed (CAN; n = 43), or no oilseed (CON; n = 43), for the last 35 d of gestation and then a common lactation diet pp. Ovaries were scanned 2x/wk until 35 DIM in 95 cows to record first appearance of 10 (DF) and 16 mm (PreOVF) follicles, and ovulation. Blood samples were collected strategically to evaluate NEFA, BHBA and glucose, and endometrial cytology performed at 25 ± 1 d pp (n = 12/diet). Data were analyzed using the Mixed procedure of SAS. Multiparous CON cows consumed more DM (19.5 ± 0.2) than those fed oilseed (18.0 ± 0.2 kg) during pre- and pp, until wk+3 pp. Cows fed SUN consumed more than those fed CAN (23.5 ± 0.2 vs 22.5 ± 0.3 kg) pp from wk+2 to wk+5. Cows fed oilseed had higher NEFA (mEq/mL) than CON at wk-3 (108.0 ± 10.3 vs. 70.8 ± 10.3), wk+1 (388.7 ± 56.2 vs. 271.0 ± 56.2), and wk+4 (242.0 ± 36.6 vs. 163.5 ± 36.6), but pre and pp energy balance (EB) did not differ (8.1 ± 1.6 Mcal). Prepartum diets did not affect BHBA (12.1 ± 1.6 mg/dL) and glucose (54.5 ± 2.9 mg/dL) pre or pp. Prepartum oilseed and type of oilseed supplemented neither altered the intervals (d) from calving to DF (9.4 ± 0.5), PreOVF (14.7 ± 0.8), or ovulation (21.4 ± 1.5), nor conception rate to first AI (27.2%) and cumulative pregnancy rate (67.3%) up to 5 AI. The interval to DF was correlated with % of polymorphonuclear cells (PMN; R: 0.38), DMI (R: −0.28) and glucose (R: −0.32) on wk+2. Interval to PreOVF was determined by % of PMN (R: 0.38) and DMI on wk −4 (R:-0.27), −3 (R:-0.27), −2 (R:-0.33),-1 (R:-0.38), +1 (R:-0.38), +2 (R:-0.45) and +3 (R:-0.39). None of the metabolites, glucose, EB, DMI or PMN affected interval to ovulation, although the latter was associated with interval to PreOVF (R: 0.41). In summary, feeding oilseeds prepartum, particularly canola, reduced DMI and increased NEFA without affecting reproductive performance.