Poor academic achievement/ performance of secondary school students in certificates examinations (WAEC &NECO) as well as in general output in and out of school environments especially in writing, expression and compution has created enormity of vices among secondary school graduands in so many offices or work places; and in the wider environment in recent years. As a result secondary school graduands all over the states in Nigeria and in particular, Edo State are loosing confidence and recognition. Hence, this study investigated the relationship between secondary school students’ self-efficacy beliefs and their academic achievement in Edo State. The study was guided by five (5) research questions and two (2) hypotheses. Population of study comprised of all senior secondary school 2 (SSSII) students of the state owned (public) secondary schools. A sample size of one thousand, two hundred and one (1,201) students drawm through multi-stage sampling technique from thirty (30) senior secondary schools, out of the three hundred and ten (310) state owned public secondary schools formed the sample size. The research design was correlational survey and self-efficacy scale (SES) instrument was used for data collection. Cronbach alpha reliability Co-efficient (internal consistency of (0.74) for (SES) was adopted by the researchers. Other instruments used in the study were end of term results or students’ achievement scores in Mathematics and English Language. Administration of research instrument was done through direct delivery approach and the data were analyzed using summated scores or aggregates, percentage, pearson (r), t-test and simple regression analysis. Hypotheses were tested at 0.05 level of singnificant and findings revealed that 546(45.5%) of the students have good self-efficacy beliefs. While 232(19.3%) of the students had excellent academic achievement/performance in Mathematics, 378(31.5%) of the students had excellent academic achievement in English Language. It was also revealed that the relationship existing between secondary school students’ self-efficacy beliefs and their academic achievement/performance was neither significant in Mathematics nor in English Language. Hence, the study concluded that there was no correlation existing between secondary school students and their academic achievement/performance in Edo State. Based on the findings, recommended that school guidance counsellors in collaboration with all stake-holders in teaching learning industry should encourage the need of self-efficacy beliefs among students and assist them to develop the concept .