The purpose of this research is to 1) determine the influence of organizational culture on teacher performance in vocational schools in Siatas Barita District, North Tapanuli Regency, partially; 2) determine the influence of principal leadership on teacher performance in vocational schools in Siatas Barita District, North Tapanuli Regency partially; 3) determine the influence of organizational culture and principal leadership on the performance of teachers in vocational schools in Siatas Barita District, North Tapanuli Regency simultaneously. The method used in this research is a quantitative research method. The population is all teachers in Vocational Schools in Siatas Barita District spread across 3 schools totaling 160 teachers and this research is population research. Data was collected using a closed questionnaire with 65 items. The results of data analysis show that: 1) the calculated Fvalue > Ftable between organizational culture and teacher performance is 198.558 > 3.00, thus it is known that there is an influence of organizational culture on teacher performance in vocational schools throughout Siatas Barita District, North Tapanuli Regency, namely 55 .7%, 2) calculated Fvalue > Ftable between principal leadership on teacher performance, namely 77.797 > 3.00, thus it is known that there is an influence of principal leadership on teacher performance in vocational schools throughout Siatas Barita District, North Tapanuli Regency, namely 33 %, 3) calculated Fvalue > Ftable between organizational culture and principal leadership on teacher performance, namely 130.666 > 3.00, thus it is known that there is an influence of organizational culture and principal leadership on teacher performance in vocational schools throughout Siatas Barita District, Tapanuli Regency North is 62.5%, thus Ha is accepted and H0 is rejected.