This dissertation sought to determine the impact of online dual enrollment (DE) coursework on first-generation students' college GPAs and persistence/graduation outcomes. Further, this dissertation intended to discover whether increased dosages of online DE coursework result in increased persistence/graduation rates of first-generation students. All data was collected from the HSLS:09 and statistical software "r" was used to conduct the analysis. Propensity score matching was employed to discover the impact of online DE coursework (possibly in conjunction with other DE coursework) on first-generation students' college GPAs during their first three years of higher education. Students were matched on eleven covariates: race, gender, socioeconomic status, urbanicity, high school GPA, and six variables pertaining to the academic and familial support that students received. The results indicate that, in this sample of first-generation students, the completion of online DE coursework was not associated with increases in college GPAs compared to students who did not take DE coursework and students who took only "In-Person DE" coursework, based on the matching of students on relevant covariates. A binary logistic regression was then conducted to determine the impact of online DE on first-generation students' college persistence/graduation. The results indicate that, in this sample of first-generation students, online DE coursework was associated with decreased likelihood of persistence/graduation. Further, this dissertation intended to determine whether the dosage of online DE coursework impacted the persistence/graduation rates of first-generation students. The results indicate that the number of high school online DE credits had no significant effect on the persistence/graduation of first-generation students. A significant limitation of this study is the limited sample size of first-generation students who completed online DE coursework prior to 2016. Since the prevalence of online DE coursework has increased, and since students may be more accustomed to the online platforms utilized during DE courses, future studies should seek to determine whether these findings hold true for today's students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]