Background: Patients often report that living with a condition such as tinnitus can be debilitating, worrying, and frustrating. Efficient ways to foster management strategies for individuals with tinnitus and promoting tinnitus self-efficacy are needed. Internet-based cognitive behavioral therapy (ICBT) for tinnitus shows promise as an evidence-based intervention in Europe, but is not available in the United States. The aim of this pilot study was to evaluate the feasibility of an ICBT intervention for tinnitus in the United States. Method: This study reports the Phase 1 trial intended to support implementation of a larger randomized clinical trial (RCT) comparing ICBT to a weekly monitoring group. As a pilot study, a single-group pretest-posttest design was used to determine outcome potential, recruitment strategy, retention, and adherence rates of ICBT for tinnitus. The primary outcome was a change in tinnitus distress. Secondary outcome measures included measures of anxiety, depression, insomnia, tinnitus cognitions, hearing-related difficulties, and quality of life. Results: Of the 42 screened participants, nine did not meet the inclusion criteria and six withdrew. There were 27 participants who completed the intervention, with a mean age of 55.48 (+/- 9.9) years. Feasibility was established, as a large pretest-posttest effect size of d = 1.6 was found for tinnitus severity. Large pretest-posttest effect sizes were also found for tinnitus cognitions and hearing-related effects, and a medium effect was found for insomnia and quality of life. Treatment adherence varied with a retention rate of 85% (n = 23) at post-intervention assessment and 67% (n = 18) for the follow-up assessment. Conclusions: This pilot study supported the feasibility of ICBT for tinnitus in the United States. Ways of improving intervention retention and recruitment rates need to be explored in future ICBT studies. Protocol refinements that were identified will be implemented prior to further RCTs to investigate the efficacy of ICBT for tinnitus in the United States.