There is currently increasing awareness of third-party disability, defined as the disability and functioning of a significant other (SO) due to a health condition of one of their family members. The effects of third-party disability on the SOs of individuals with tinnitus has received little attention. To address this knowledge gap, this study investigated third-party disability in the significant others (SOs) of individuals with tinnitus. A cross-sectional survey design included 194 pairs of individuals from the USA with tinnitus and their significant others. The SO sample completed the Consequences of Tinnitus on Significant Others Questionnaire (CTSOQ). Individuals with tinnitus completed standardized self-reported outcome measures for tinnitus severity, anxiety, depression, insomnia, hearing-related quality of life, tinnitus cognitions, hearing disability, and hyperacusis. The CTSOQ showed that 34 (18%) of the SOs were mildly impacted, 59 (30%) were significantly impacted, and 101 (52%) were severely impact. The clinical variables of tinnitus severity, anxiety, and hyperacusis in individuals with tinnitus were the best predictors of the impact of tinnitus on SOs. These results show that the SOs of individuals with tinnitus may experience third-party disability. The effect of the individual’s tinnitus on their SO may be greater when the individual with tinnitus has a higher level of tinnitus severity, anxiety, and hyperacusis.