Introduction: Transoral endoscopic thyroidectomy vestibular approach (TOETVA) has become increasingly popular. Several reports have emphasized the safety and efficacy of this new approach. However, there is no report on functional voice outcomes, including voice pitch change after TOETVA. Methods: The functional voice outcomes of patients undergoing TOETVA were compared with those of patients undergoing conventional thyroidectomy. A total of 82 consecutive patients were included in the study: 44 underwent thyroid lobectomy via TOETVA (transoral group) and 38 underwent thyroid lobectomy via the classic cervical approach (open group). Thyroidectomy-related voice questionnaire (TVQ), perceptual voice analysis, fiberoptic laryngoscopic and videolaryngostroboscopic examinations, and acoustic analysis were carried out before and one month after surgery. The changes in these values after surgery and the differences between the transoral and open groups were analyzed. Results: We found no significant postoperative change in voice workups in either group. The mean high pitch decreased (from 367.91 ± 120.98 to 325.80 ± 100.86 Hz, p = 0.069) in the transoral group, but statistical significance was not attained. Clinically significant changes in pitch (postoperative change in speaking fundamental frequency, ΔSFF ≥ 12) after surgery were evident in seven (15.91%) patients in the transoral group and eight (21.05%) patients in the open group without significant difference (p = 0.579). Conclusions: This is the first study to assess functional voice outcomes (including pitch) after TOETVA compared with conventional open surgery. TOETVA was associated with good voice outcomes without any significant drop in pitch.