This quantitative study aimed to investigate the influence of teacher personality on teacher-student relatedness, student intrinsic motivation, and academic performance. The pressing need to understand the factors influencing educational outcomes driving this study arises from the desire to enhance teaching effectiveness and student success. By comprehensively examining the influence of teacher personality traits on teacher-student relatedness, student intrinsic motivation, and academic performance, educators and policymakers can develop targeted interventions and strategies to optimize learning environments and improve overall educational outcomes. Using the Big Five Trait Theory, the current study elucidated the relationships between specific teacher personality traits: openness, conscientiousness, extraversion, agreeableness, and neuroticism, and key aspects of education, including teacher-student relatedness, student intrinsic motivation, and academic performance. The study employed a cross-sectional research design and gathered data from 106 teachers representing diverse demographics, all of whom taught the sampled 160 senior-level students, age 18 years or older, within the past two years. Online surveys were administered to gather the data and subsequently analyzed to explore the associations between teacher personality traits and the study students' outcome variables, meticulously delineating specific dimensions of teacher personality traits and student outcome variables within the educational context. The study's findings revealed noteworthy insights. The findings highlighted the crucial role of teacher agreeableness in fostering positive teacher-student relatedness. This finding underscores the importance of cultivating agreeable traits in educators, implicating teacher training programs and school cultures. The findings did not reveal statistically significant correlations between teacher personality traits and student intrinsic motivation. This outcome implies that multifaceted factors beyond the teacher's personality might influence students' intrinsic motivation, emphasizing the need for diverse motivational strategies. Thirdly, the study revealed that teacher personality traits did not significantly predict student test scores. The study's findings collectively emphasized the multifactorial nature of academic achievement, highlighting the necessity of holistic educational approaches. Lastly, the current study established a modest yet statistically significant effect of teacher gender on student test scores, emphasizing the importance of investigating factors contributing to gender-related disparities in student outcomes. [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.]