Background: Global COVID-19 vaccination effort faces the challenges of vaccine hesitancy and resistance, rooted in misinformation and institutional distrust. Addressing these barriers with customized messaging is essential, yet the relationship between vaccine hesitancy and other health-seeking behaviors, like COVID-19 testing, has been underexplored. Method: This study assessed COVID-19 vaccine uptake in Southeastern Louisiana across 10 pharmacies and clinics in areas with historically high rates of COVID-19 infection. Using a longitudinal cohort design from Fall 2022 through Fall 2023, a total of 377 participants from diverse backgrounds were surveyed while seeking routine care at partner organizations. Baseline data was collected on demographics, vaccine knowledge, attitudes, and test-seeking behaviors. Information on COVID-19 testing and vaccination were self-reported and verified, as applicable, in the patient’s medical records. All data was analyzed using descriptive statistics, log-binomial to yield risk ratios, and an ordinal logistic regression for vaccine series completion. Results: Among the 377 participants, 207 were unvaccinated while 170 received the vaccine. Among the unvaccinated individuals, 53 received a half-dose, 97 a full dose, and 14 a booster. Notably, 75% of unvaccinated and 89% of vaccinated participants underwent COVID-19 testing. Individuals who were tested were 1.71 times more likely to be vaccinated (95% CI 1.03, 2.84), while previous vaccine refusal was associated with lower vaccine acceptance (0.77; 95% CI 0.54, 1.09). In the bivariate and multivariate analysis, COVID-19 testing behavior was positively associated with COVID-19 vaccine uptake. Conclusions: Exploring the connection between COVID-19 testing and vaccination provides valuable insights for future public health messaging to mitigate vaccine hesitancy.