Teacher turnover jeopardizes school effectiveness and contributes to teacher shortages directly impacting student learning. The problem addressed by this study was the negative impact of turnover in Texas Fast Growth School Coalition Districts' newly hired teachers. The purpose of this quantitative correlational study aimed to analyze the potential relationship between newly hired K-12 teachers' socialization level, onboarding perception, and intent to leave during or at the end of their first year while in a Texas Fast Growth School Coalition District. The theoretical framework underpinning this study was Organizational Socialization Theory. A quantitative correlational non-experimental design was used in this study and incorporated a linear regression analysis. Data from 136 participants were analyzed using descriptive statistics and Pearson's coefficient correlation analysis to answer the research questions. Three established instruments consisting of 56 items were combined into one questionnaire and used for data collection. Linear regression models confirmed onboarding was a significant predictor of intent to leave with (F (1, 134) = 86.394, p < 0.001, with an R[superscript 2] of 0.392 and R[superscript 2] Adjusted 0.387. Linear regression models also confirmed that socialization level was a significant predictor of intent to leave, (F (1, 136) = 15.167, p < 0.001, with an R[superscript 2] of 0.10 and R[superscript 2] Adjusted = 0.094. Lastly, linear regression models also confirmed that Socialization Level & Onboarding was significant predictor of Intent to Leave, (F (1, 136) = 27.668, p < 0.001, with an R[superscript 2] of 0.169 and R[superscript 2] Adjusted = 0.163. This study validated the connection between organizational socialization, onboarding, and employee turnover, as posited in academic research. Implications of this research was that whenever teachers are onboarded effectively and express higher socialization levels, they can adapt and learn the ropes more efficiently, which lowers their turnover intentions. Based on the findings school districts should refine their socialization efforts to effectively raise the socialization level of teachers through robust onboarding and induction processes. Although the data findings from this research study established that onboarding and socialization levels were significant predictors of intent to leave, some limitations need to be addressed for future researchers such as the sample population. [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.]