This is a randomized, double-blind, placebo-controlled Phase II study designed to determine if amoxicillin will eradicate vaginal colonization/infection with Gardnerella vaginalis (GV) when administered to women who are colonized/infected with GV but have no clinical evidence of Bacterial Vaginosis (BV). The study will be conducted at 2 clinics in the United States: University of Alabama at Birmingham and Wake Forest University Health Sciences. Entire study duration is approximately 10 months and subject participation duration is approximately 15 days. Approximately 245 healthy adult females, 18 to 45 years of age will be screened to enroll approximately 98 participants to achieve 82 evaluable participants at the test of cure (ToC) visit. Women who consent to screening participation will undergo pelvic examination on entry and vaginal specimens collected for pH, whiff test and wet prep microscopy (Amsel criteria with the exception of evaluation of vaginal discharge), Nugent score, nucleic acid amplification test (NAAT) for trichomonas, quantitative NAAT for GV, and microbiome analysis. At Visit 1 (Enrollment - Day 1), women who tested positive for GV by NAAT, negative for BV by Nugent, and negative for trichomonas by NAAT will be enrolled and randomized to one of two groups, either amoxicillin (2 x 250 mg capsules by mouth twice daily for 7 days) or placebo. Women who are enrolled will be asked to return for one further visit, Visit 2 (Day 15 - 21), where a ToC will be completed (a pelvic exam completed with the same specimens taken as those at baseline with the exception of the trichomonas NAAT). For those not enrolled, participation will end at their post screening follow up phone call. Women will be asked to use condoms during their participation. The primary objective is to determine if treatment with amoxicillin eradicates GV in women who are colonized/infected with GV but have no clinical evidence of BV. The secondary objective is to evaluate the safety and tolerability of amoxicillin compared to placebo.