This study aimed to evaluate the effects of the blend of babassu oil (BO) and sunflower oil (SO) in different proportions on performance, quality, and fatty acid (FA) composition in lamb meat. Feeding BO reduced (P = 0.019) dry matter intake, energy intake (P = 0.029), final body weight (P = 0.043), dressing percentage (P = 0.051), and subcutaneous fat thickness (s.c. fat
P = 0.020) but did not change meat quality traits. The SO blend addition performed a quadratic effect (P <
0.05) on the nutrient intake, without affect carcass characteristics. Dietary BO diet increased (P <
0.05) trans-monounsaturated fatty acids (trans-MUFA) in meat and s.c. fat. However, saturated FA (SFA) and polyunsaturated FA (PUFA) in meat did not change. No difference in trans-MUFA content was found (P = 0.810) when adding SO blend to the diet. The lipid supplementation did not affect (P >
0.05) the PUFA proportion in s.c. fat, but BO reduced (P <
0.05) branched-chain fatty acids, cis-monounsaturated fatty acids (cis-MUFA), and 18:0-oxo compared to the unsupplemented diets. Dietary SO blend inclusion did not extensively modify productive and neither meat quality traits, compared to BO solely addition. However, the addition of 18.6 g/kg of SO blend increased cis-MUFA content in meat and BCFA in s.c. fat, representing an alternative for the local Amazon producers which already utilize this source of lipid.