This study examined the relationship between science self-efficacy, meta-variables (meta-awareness, meta-regulation, meta-monitoring, and meta-evaluation), and students' critical thinking in Biology among secondary school students in Kogi East, Nigeria. Guided by 6 research questions, 6 null hypotheses were tested at a 0.05 significance level. The study adopted a correlational design.

The population included 9001 Senior Secondary 2 students, with a sample of 382 students selected from five schools using a multistage sampling technique. Data were collected using the researcher-designed Biology Critical Thinking Test (BCTT), Biology Self-Efficacy Scale (BSES), and Biology Meta-Variable Scale (BMVS). These instruments were validated by experts in science education and measurement and evaluation and trial tested.

The reliability coefficients of 0.80 (BCTT), 0.89 (BMVS), and 0.82 (BSES) were found. Regression analysis addressed research questions, while ANOVA tested the hypotheses. Results indicated that Science self-efficacy positively correlated with critical thinking (r = 0.124, R² = 0.015). Meta-awareness, meta-regulation, meta-monitoring, and meta-evaluation significantly correlated with critical thinking, with meta-evaluation showing the strongest relationship (r = 0.840, R² = 0.706).

The combined influence of science self-efficacy and meta-variables on Biology critical thinking (r = 0.188, R² = 0.035) was also significant. Findings suggest that higher science self-efficacy enhances critical thinking in Biology.

Meta-variables play a crucial role in shaping students' learning outcomes. The study recommends improving Biology instruction through active engagement methods such as problem-solving tasks, group discussions, and real-world applications. Encouraging critical thinking through case studies, debates, and scientific investigations, along with inquiry-based learning, can further enhance students' analytical abilities.