The objective was to evaluate replacement of corn with crude glycerin (CG) in high-concentrate, low starch diets on fatty acid profile of meat. Forty Santa Ines lambs (23.5 ± 1.35 kg BW) were assigned to a randomized block design with 5 treatments: 0, 7.5, 15, 22.5, and 30% of CG (DM basis). The diet with 30% of CG promoted total replacement of corn. The diets consisted of Tifton-85 hay, corn, CG (83% glycerol), corn gluten meal, corn oil, urea, sunflower meal, soybean hulls and mineral. All diets had around 18% roughage and 82% concentrate. The animals were housed in individual pens and fed ad libitum twice daily at 0700 and 1600 h. The experimental period had 72 ± 7 d of duration and animal harvest was performed when the animals had reached 38 kg BW. Orthogonal contrasts were used to determine the linear and quadratic effects of CG and also constrast of 0% CG vs. CG treatments was used. Odd-chain fatty acids (C15:0, C17:0 and C17:1), oleic (C18:1), palmitoleic (C16:1), total monounsaturated, total unsaturated fatty acids, and their ratios to saturated fatty acids increased linearly within increasing CG. The concentration of all these fatty acids and the ratios, except C16:1, were greater in animals fed any concentration of CG compared with animals fed without CG (P < 0.01). The CLA tended to increase in glycerin-fed lambs (P = 0.06). The CG decreased linearly the stearic (C18:0), palmitic (C16:0), transvaccenic (C18:1 t11) and total saturated fatty acids (P < 0.01). The myristic acid (C14:0) tended to decrease quadratically with increasing CG (P = 0.06). The concentration of C18:0, C16:0, C14:0 and total saturated fatty acids decreased when CG was added, regardless of concentration (P ≤ 0.02). The C18:1 t11 tended to be present in greater concentrations in animals fed without CG compared with animals fed CG (P = 0.09). Crude glycerin can be a viable alternative as an energy source in the diet of lambs fully replacing corn into low-starch diets, providing meat with healthier fatty acid profile.