Heterotrophic microalgae can be manipulated to contain specific fatty acids; however, it is unknown how these differences may affect nutrient digestibility in ruminants. Algae meal (ALG) contains delipidated algae (57% DM basis) and soyhulls (43%). To determine the impact of replacing corn with ALG of differing fatty acid profiles, high oleic acid (HE) or high lauric acid (HL), on nutrient digestibility, 10 whiteface wethers (27.9 ± 0.87 kg) were used in a replicated 5 × 5 Latin square. There were 5 periods, with 10 d of adaptation and 5 d of fecal and urine collection. Sheep (n = 2 sheep·diet⁻¹·period⁻¹) received one of 5 finishing diets containing corn, 35% corn silage, 5% hay, 10% soybean meal, and 5% micro ingredients: a corn-based control (CON), 18% HE ALG (18HE), 36% HE ALG (36HE), 18% HL ALG (18HL), and 36% HL ALG (36HL). Both the HE and HL ALG were similar in nutrient composition except for fat (15.8 and 8.19%, respectively) and K (1.6 and 5.4%, respectively). Pooled SEM and LSMEANS are reported. Intake of DM linearly (P < 0.01) increased as either ALG increased in the diet; however, DMI was less (P < 0.01) for 18HE-fed lambs vs. 18HL-fed lambs. Urine output linearly (P < 0.001) increased as ALG increased in the HL-fed lambs and was less (P < 0.001) for 36HE-fed lambs vs. 36HL-fed lambs. Digestibility of DM linearly (P ≤ 0.04) decreased as both HE and HL ALG increased in the diet (75.2, 73.9, 70.1, 73.2, and 72.7 ± 0.82% for CON, 18HE, 36HE, 18HL, and 36HL, respectively). Lambs fed 36HE had less (P = 0.03) DM digestibility than those fed 36HL. Digestibility of NDF linearly (P = 0.04) increased in lambs fed HL diets (47.7, 51.6, 54.5 ± 2.18 for CON, 18HL, and 36HL, respectively). Fat digestibility linearly (P ≤ 0.02) increased as either ALG increased in the diet; however, digestibility was less (P < 0.001) for 36HE-fed lambs than 36HL-fed lambs. Both ALG are highly digestible and could serve as viable feedstuffs in feedlot diets. Due to varying inclusions of fat and K within the strains of algae it was difficult to ascertain if the fatty acid profile had any effect on nutrient digestibility.