Purpose Thyroidectomy is the main treatment for thyroid cancer, a disease with rapidly increasing incidence in Australia. This study compared quality of life (QOL) outcomes after hemithyroidectomy (HT) and total thyroidectomy (TT), information that could assist surgical decision making and optimise outcomes for thyroid cancer patients and survivors. Methodology A prospective cohort study was conducted, including adults diagnosed with thyroid cancer who had undergone a HT or TT within the Australian and New Zealand Thyroid Cancer Registry. Patients who underwent subsequent completion HT were excluded. Quality of life outcomes were measured at 3, 6 and 12 months postoperatively using the internationally validated EORTC C30 and THY34 instruments, examining domains of cognitive, emotional, physical, social and role functioning. Linear mixed-effects models were used to assess the changes in QOL outcomes over time between HT and TT. Results The sample for analysis included 498 patients with thyroid cancer, 187 who had undergone HT and 311 TT. The majority of participants were females (77.0%) and the mean age was 53 years. Papillary carcinoma was the predominant histology (85.0%). Social and role functioning were significantly better in the HT group (p=0.043) in the early postoperative period. By 12 months, there was no difference between groups in all domains. Conclusion Though HT patients reported better scores in role functioning in the early postoperative period, both HT and TT patients had good functional quality of life by 12 months post-surgery. These findings are useful for preoperative counselling and setting expectations.