The effects of dietary supplementation with Azolla pinnata (a macro algae) on lamb performance, blood parameters, carcass traits and meat quality were investigated. Thirty fat-tail uncastrated male Moghani lambs with an initial average body weight (BW) of 28 ± 1.4 kg were allocated to one of three dietary treatments (10 lambs/treatment) by stratified randomisation based on BW. Lambs were fed ad libitum for 90 d with a standard finishing diet containing sun-dried Azolla at 0, 10 and 20 % (DM basis) levels. Results showed that the feed intake tended to be lower (P = 0.074) in Azolla supplemented lambs, the values were 1.73 and 1.69 and 1.48 kg DM/d, for 0, 10 and 20 % Azolla, respectively. Plasma urea and creatinine concentrations were lower in Azolla supplemented lambs than control group (P < 0.05). BW was not affected by dietary supplementation of Azolla (P> 0.05) but inclusion of Azolla in the feedlot ration improved (P = 0.004) feed conversion ratio. Hot and cold carcass weights were greater (P = 0.009) for lambs fed with 10 % Azolla (24.9 and 24.4 kg), than for the control group (22.5 and 22.1 kg, respectively). Other carcass traits and longissimus muscle chemical composition were not impacted by Azolla supplementation (P > 0.05). Lambs that were supplemented with 20 % Azolla in the feedlot ration had greater odor intensity scores (P = 0.01) compared with the control group. The sensory properties of meat were not altered by 10 % Azolla diet. Azolla supplementation at 10 % and 20 % had no effect on meat quality attributes (P > 0.05). From these results, the supplementation of Azolla pinnata at 10 % level is recommended as a feed source to improve feed conversion ratio and carcass weights for Moghani lambs, without compromising meat quality and sensory properties.