Although tension-type headache (TTH) is a frequent type of headache disorder and imposes a significant burden, there is scant information about the prevalence and impact of comorbid anxiety and depression among individuals with TTH. We investigated the prevalence and clinical impact of anxiety and depression among patients with TTH in the general population. We recruited Korean participants aged 19–69 years using a two-stage clustered random sampling method. To identify the presence of headache type, anxiety, and depression, we used a semi-structured interview using certain questionnaires. To assess the level of anxiety and depression, we used the Goldberg Anxiety Scale and Patient Health Questionnaire-9, respectively. Among 2,695 participants, 570 people (21.2%) had TTH during previous 1 year. In participants with TTH, the prevalence of anxiety (9.5% vs. 5.3%, p = 0.001) and depression (4.2% vs. 1.8%, p = 0.001) was significantly higher than that of non-headache participants. The prevalence of anxiety among TTH participants with >15 attacks per month [21.4%, odds ratio (OR): 4.0] and 1–14 attacks per month (13.1%, OR: 2.2) was higher than that in those with <1 attack per month (6.4%), however this tendency was not observed in participants with depression. Visual Analogue Scale (VAS) score [median 5.0 vs. 4.0, p = 0.010] and Headache Impact Test-6 (HIT-6) score [median 45.5 vs. 42.0, p < 0.001] were significantly higher among those with anxiety. Furthermore, VAS scores [median 5.0 vs. 4.0, p = 0.010] and HIT-6 scores [median 45.5 vs. 42.0, p = 0.027] were also significantly higher among TTH patients with depression than among those without depression. In conclusion, anxiety and depression were more prevalent in participants with TTH than in non-headache participants. These two conditions were associated with an exacerbation of headache symptoms in individuals with TTH.