The study explored the effects of levomethadone and ketamine on postoperative pain and activity in calves following hot-iron disbudding. Twenty-eight dairy calves, aged 21 ± 5 d (mean ± SD) and weighing 61.2 ± 9.4 kg, were randomly assigned to 1 of 3 intramuscular sedation protocols administered 30 min before disbudding: group XL (levomethadone 0.05 mg/kg and xylazine 0.1 mg/kg), group XK (ketamine 1 mg/kg and xylazine 0.1 mg/kg), and group X (xylazine 0.2 mg/kg). All calves received subcutaneous meloxicam (0.5 mg/kg) and a local anesthetic (procaine hydrochloride, 4.5 mg/kg) 15 min before heat cauterization of the horn buds. Pain was assessed using a multidimensional composite pain score (CPS) and visual analog pain score, pressure pain threshold with algometry, tactile sensitivity with von Frey microfilaments, and peri-bud swelling at baseline and predetermined time points up to 24 h postdisbudding. Additionally, calf activity before and after disbudding was monitored using an accelerometer attached to the foreleg. Pairwise contrasts were performed using ordinal logistic regression, with odds ratios (OR) and 95% CI reported. Calves in group XK showed higher pain scores compared with groups X and XL, with median (interquartile range [IQR]) CPS values of 14 (IQR: 11.5-15.25) at T180 and 8 (IQR: 6.75-9.25) at T240 (OR = 8.72 and 15.96; 95% CI: 1.33-57.05 and 2.13-119.82, respectively) versus 9 (IQR: 8-9.75) and 6.5 (IQR: 6-7.75) in XL, respectively. Likewise, a similar pattern was observed between XK and X (T240 OR = 14.11, 95% CI 1.96-101.49; T24 h OR = 11.43, 95% CI 1.69-77.09). Pressure pain thresholds at 24 h were lower in XK (9 [IQR: 8-11] N) and X (9.5 [IQR: 8-13] N) compared with XL (17.5 [IQR: 14-19.5] N). Correspondingly, tactile sensitivity scores were higher in XK and X compared with XL (OR = 6.66, 95% CI: 0.89-49.55 for XK vs. XL; OR = 8.21, 95% CI: 1.19-56.32 for X vs. XL). No consistent treatment differences were detected in peri-bud swelling scores. Activity levels were largely comparable across groups; however, calves in group X spent less time lying during the first night postdisbudding compared with the preceding night (mean difference: -24 min, 95% CI: -42 to -5), suggesting reduced resting behavior. The findings from this preliminary study suggest that the combination of levomethadone with low-dose xylazine provided superior short-term pain control and improved postdisbudding comfort compared with ketamine-xylazine or xylazine alone. However, given the limited sample size, these results should be interpreted with caution, and larger-scale studies are needed to confirm whether incorporating opioids into sedation protocols can reliably enhance calf welfare following disbudding.