This study was undertaken to determine the influence of social environment indices on students’ academic achievement in Civic Education in public secondary schools in Cross River State, Nigeria. In line with the specific objectives of the study, four research questions were set and four null hypotheses were accordingly formulated to guide the study. The ex-post facto research design was adopted for the study. The study population comprised all the 9,696 Senior Secondary-Two Students in the 193 public secondary schools in Cross River State, Nigeria in the 2023/2024 academic session. 969 Students (10%) of the study population were selected as the sample size for the study. An instrument entitled “Social Environment Indices and Academic Achievement Questionnaire (SEIAAQ)” was used to collect data for the study. The instrument was given a face validation by experts in Test and Measurement. While, the reliability estimate of the instrument was determined using the Cronbach’s Alpha Correlation Coefficient statistics. Data collected were first described using Mean and Standard Deviation statistics before they were analysed using the One-way Analysis of Variance (ANOVA) and ‘Z’-test statistics at 0.05 level of significance. The findings were that family structure, peer-group and social media usage have significant influence on students’ academic achievement in Civic Education, while school location does not have any significant statistical influence on academic achievement in Civic Education. Based on the findings, it was recommended among other things that there is a need for the school authority and parents to checkmate students’ social media usage to avoid addiction, so that students' academic achievement in Civic Education in Cross River State will not continue to be a mirage.