Aim: To compare the efficacy and safety of bupivacaine with clonidine versus bupivacaine alone in thoracic paravertebral block for patients undergoing simple breast surgery. Material and Methods: This prospective, randomized, comparative clinical study was conducted over a one-year period from July 2022 to June 2023 in the Department of Anesthesiology at a tertiary care teaching hospital. A total of 100 female patients aged 20–65 years scheduled for elective simple breast surgeries were randomly assigned into two groups: Group BC (n = 50) received 0.5% bupivacaine with clonidine 1 µg/kg, and Group B (n = 50) received 0.5% bupivacaine alone. Outcome measures included onset and duration of sensory block, postoperative pain scores using the Visual Analog Scale (VAS), total analgesic consumption within 24 hours, hemodynamic stability, and adverse effects. Results: Group BC showed a significantly faster onset (7.42 ± 1.3 min vs. 8.78 ± 1.5 min; p< 0.001) and prolonged duration of analgesia (408.6 ± 52.8 min vs. 276.4 ± 48.2 min; p< 0.001) compared to Group B. VAS scores were significantly lower in Group BC at all time intervals up to 24 hours postoperatively (p< 0.001). Rescue analgesic requirement was lower in Group BC (28%) compared to Group B (72%) with significantly reduced diclofenac consumption (48.2 ± 10.4 mg vs. 92.6 ± 14.8 mg; p< 0.001). Hemodynamic parameters remained stable, and adverse effects were minimal and comparable between groups. Conclusion: Clonidine as an adjuvant to bupivacaine in paravertebral block provides faster onset, longer duration of analgesia, superior postoperative pain relief, and reduced analgesic consumption without increasing adverse effects, making it a safe and effective option for breast surgeries.