Background: Hashimoto’s thyroiditis (HT) is a prevalent autoimmune cause of hypothyroidism, with many patients reporting dizziness and imbalance. These vestibular symptoms may negatively impact quality of life (QoL). The relationship between HT, vestibular dysfunction, and daily functioning remains underexplored. The work aims to assess vestibular function in patients with HT and how vestibular dysfunction would affect QoL. Methods: This cross-sectional, case–control study was conducted on 72 adults divided into three equal groups: control, HT patients without dizziness (HNC), and HT patients with dizziness (HC). Participants underwent history taking, otoscopic and audiological examinations, videonystagmography (VNG), cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP), and thyroid hormonal/autoimmune profiling. Self-assessment tools (Arabic versions of the Dizziness Handicap Inventory [DHI] and Vestibular Activities of Daily Living [VADL]) were applied in the HC group. Results: The three groups did not differ significantly regarding pure tone audiometry and oculomotor tests. Vestibular abnormalities were significantly higher in HC patients. In HC group, caloric test abnormalities were detected in 50%, cVEMP abnormalities in 50%, and oVEMP abnormalities in 41.6%. The HNC group showed cVEMP and/or oVEMP abnormalities in 25%. Self-assessment scores confirmed moderate handicap on DHI and reduced functional, ambulation, and instrumental scores on VADL, particularly during attacks. Conclusion: HT is associated with vestibular dysfunction, even in patients without dizziness. Peripheral vestibular dysfunction was the most common abnormality. Vestibular testing and self-assessment questionnaires highlight both objective and subjective impairments, underlining the need for routine vestibular evaluation.