The aim of this study was to investigate the effects on meat quality of crossbred bulls finished in a feedlot when some corn is replaced by glycerin and essential oils (EO) are added to the diet. Thirty bulls weighing 311 kg ± 28.8 kg (22 ± 2 months old) were randomly assigned to one of three diets: CON – Control (diet without glycerin and EO); GLY – 16.1% glycerin in dry matter (DM); and GEO – 16.1% glycerin in DM and EO (cashew: Anacardium occidentale; castor: Ricinus communis) at 442 mg/kg DM consumed. The bulls were kept in a feedlot for 115 days and slaughtered at an average weight of 467 ± 27.9 kg (25 ± 2 months old). The bulls were fed on sorghum silage, cracked corn, glycerin, soybean meal, urea, limestone, and mineral salt. Replacing corn with glycerin plus EO adding to the diet had no effect on the fat thickness, Longissimus muscle (LM) area, marbling, texture, colour, Warner–Bratzler shear force, or chemical composition of the LM. The fatty acid composition in the LM was similar among the diets, except for percentages of myristic and margaric acids. The diets had no effect on the percentage of saturated and polyunsaturated fatty acids. Animals fed on glycerin had a lower ratio of n-6 to n-3 in the LM when compared with the CON diet. Partial replacing of corn with glycerin and EO improved meat flavour, tenderness, and the preference of consumers. Corn may be replaced by glycerin to a 15% level of DM without any detrimental effect on the carcass characteristics or the chemical composition of the LM.