This study was conducted to evaluate the effect of ferulic acid (FA) and clinoptilolite (CTL) supplementation on the growth performance, carcass characteristics, and meat quality of hair-breed lambs. Twenty-eight Kathadin male lambs (33.72 ± 3.4 kg) were randomly allocated to one of the four diets (n=7) under a 2 × 2 factorial arrangement to evaluate the effect of FA (0 or 300 ppm) and CTL (0% or 1%) during the last 40 days of the finishing phase. No interaction between additives was shown for growth performance, carcass characteristics and meat quality, with exception of the fatty acid profile ( p < 0.05). FA reduced feed intake and carcass conformation ( p < 0.05). Wholesale cuts were not affected by FA or CTL ( p > 0.05). The L*, a*, and C* color parameters and some intramuscular fatty acids of the longissimus thoracis muscle were positively modified by CTL supplementation ( p < 0.05). While there was no FA × CTL interaction, each additive could be used individually in animal nutrition to improve the feedlot performance and meat quality of the lambs.