Abstract: This study examined the relationship between principals’ idealized influence and academic performance in secondary schools in Bureti Sub-County, Kenya. Idealized influence, a key dimension of transformational leadership, reflects principals’ ability to act as ethical role models, demonstrate integrity, and inspire teachers and learners through exemplary conduct. The study was informed by persistent variations in KCSE performance across schools despite operating under similar policy and resource frameworks. A correlational research design was adopted, targeting 54 secondary schools, from which 10 Extra County schools were purposively selected and categorized into high-performing and low-performing schools based on five-year KCSE mean scores (2018–2022). The study involved a census of 10 principals and a sample of 184 teachers selected using Krejcie and Morgan sampling procedures and simple random sampling. Data were collected using a modified Multifactor Leadership Questionnaire (MLQ) and principal interview schedules. Quantitative data were analyzed using descriptive statistics and logistic regression, while qualitative data were analyzed thematically. Reliability coefficients ranged from 0.838 to 0.881. Findings revealed that principals demonstrated a moderate level of idealized influence (M = 3.04, SD = 0.65). Inferential results showed that idealized influence had no statistically significant relationship with academic performance classification (B = -0.110, SE = 0.226, p = 0.628), although a weak negative association was observed. The study concludes that while idealized influence contributes to shaping school culture and professional values, it doesn’t predict academic performance, suggesting the influence of broader contextual and instructional factors.