<![CDATA[The objectives of this study are: 1) to determine the positive and significant influence of principal leadership on teacher performance in vocational high schools in Siborongborong District Year 2026; 2) to determine the positive and significant influence of organizational culture on teacher performance in vocational high schools in Siborongborong District Year 2026; and 3) to determine the simultaneous positive and significant influence of principal leadership and organizational culture on teacher performance in vocational high schools in Siborongborong District Year 2026. This study employs a descriptive quantitative method. The population consists of 122 vocational high school teachers in Siborongborong District, and a sample of 62 individuals—representing 50% of the population—was selected. Instrument testing was conducted on 32 teachers from SMKN 2 Siatas Barita outside the study sample, confirming that all research instruments were valid and reliable as they met the established validity and reliability criteria. Data were collected using a closed-ended questionnaire comprising 60 items. The data analysis results indicate that: 1) the Fcount > Ftable (k; n-2) (2;60) is 25.876 > 3.15, demonstrating a positive and significant effect of principal leadership on teacher performance in vocational high schools in Siborongborong District Year 2026, contributing 30.1%); 2) the Fcount > Ftable (k; n-2) (2;60) is 21.309 > 3.15, demonstrating a positive and significant effect of organizational culture on teacher performance in vocational high schools in Siborongborong District Year 2026, contributing 26.2%; and 3) the Fcount > Ftable (k; n-2) (2;60) is 15.676 > 3.15, demonstrating a simultaneous positive and significant effect of principal leadership and organizational culture on teacher performance in vocational high schools in Siborongborong District Year 2026, contributing 34.7%. Consequently, the alternative hypothesis (Ha) is accepted, and the null hypothesis (H0) is rejected.]]>
