A study was conducted with the objective to assess the effects of feeding regimes on carcass measurements and proximate composition of finishing Blackhead Ogaden (BHO) sheep. Twenty-four lambs with mean initial body weight of 17.3 ± 0.52 kg were blocked into 6 groups of four lambs based on weight. Lambs in each block were randomly assigned to one of the four dietary treatments. During the growth phase, natural grass hay was offered ad libitum and a mixture of Acacia albida and Cactus pear (Opuntia ficus-indica) (at the ratio of 2:1, respectively) was supplemented at the rate of 0.9% (0.9ACM (acacia-cactus mixture), 1.2% (1.2ACM) and 1.5% (1.5ACM) of lambs body weight. Lambs in control treatment (0ACM) did not receive the supplement. During the finishing phase, roughage composed of natural grass hay and haricot bean hauls at 50:50 ratio and concentrate supplement composed of 69% wheat bran and 31% oil seed meals (noug and cottonseed cakes at the ratio of 1.1:1) were fed at roughage (R) to concentrate (C) ratios of 60R:40C, 50R:50C, 40R:60C, and 30R:70C. The percentages of roughage and concentrate were determined based on ad libitum consumption of individual animal on dry matter (DM) basis. After the completion of stall feeding, all animals were slaughtered for carcass compositions and linear measurements evaluation. Except the anterior buttock circumference (ABC) and chest depth, all carcass measurements did not vary (p > 0.05) due to feeding regimes. Lambs fed 1.5ACM/30R:70C had (p < 0.05) wider ABC than other treatment groups. Similarly, greater chest depth was recorded for groups in 1.5ACM/ 30R:70C than 0ACM/60R:40C, but the values for the rest treatments were similar. Most carcass compositions did not affect as a result of different feeding regimes, but fat content followed a similar trend to that of chest depth.