Jailed women are four-five times more likely to have had cervical cancer compared to women without criminal justice histories. Previous research has shown that an important contributor to cervical cancer risk, and perhaps lack of follow-up, is incarcerated women's low health literacy about broader reproductive health issues. Little work has been done to address this disparity. Thus, the objective of this study was to test the effectiveness of an intervention to improve incarcerated women's cervical health literacy and ultimately address cervical cancer disparities. Using a waitlist control design, we compared changes in cervical health literacy (knowledge, beliefs, self-efficacy, and confidence for screening and follow-up) among 188 incarcerated women who completed a 10-hour intervention between 2014 and 2016 in three Kansas City jails. We used bivariate tests and multivariate analyses that controlled for baseline cervical health literacy level and key covariates. Women in the intervention group showed significant gains in seven out of eight cervical health literacy domains (all p < 0.01), whereas the control group only improved in one domain (p < 0.01). When controlling for covariates, the intervention group had less barriers, perceptions of seriousness, susceptibility to disease, and increased self-efficacy for cervical health screening and follow-up, compared to the control group (all p < 0.05). A brief intervention is an effective way to improve jailed women's cervical health literacy, but should be provided alongside systemic efforts that expand access to correctional preventive health services, including the human papillomavirus vaccine, community-based cancer screenings, and health insurance after women leave jails and transition back to communities.