This study investigated the relationship between locus of control orientation and school adjustment of orphaned and vulnerable pupils (OVP) in primary schools in Kisumu Central Sub County, Kenya. It adopted a correlational research design. Purposive and snowball sampling techniques were used to sample 284 participants which included 248 OVP and 36 class teachers. Data was collected using an adapted form of Nowicki-Strickland locus of control scale for children (N-SLOC) and a modified form of teacher rating scale of school adjustment (TRSSA). The instruments were piloted in two schools to determine their validity and reliability. Content validity was ascertained by incorporating results of the pilot study and views of experts in the Department of Educational Psychology of Masinde Muliro University of Science and Technology. On the other hand, split-half technique corrected by Spearman-Brown formula was used to determine reliability of the data collection instruments. N-SLOC yielded a reliability coefficient of .793 while TRSSA, .995. Data was analysed using inferential statistics at .05 level of statistical significance and 95% confidence level. Statistical package for social sciences (SPSS) version 25 aided in the analysis. Results revealed a weak significant positive correlation between locus of control orientation and school adjustment, r = .183, df = 246, p < .05 . Recommendations were made that could help stakeholders respond to OVP in ways that increase their comfortability and ultimate adjustment in the school environment. Key words: Adjustment, locus of control orientation, orphan, school adjustment and vulnerable pupil. DOI : 10.7176/JEP/11-21-16 Publication date :July 31st 2020