The aim of the study was to investigate the influence of gender stereotype as a predictor of secondary school students' selfconcept and academic achievement. The study was guided by four purposes, four research questions, and four hypotheses. The study adopted ex post facto design. The research sample was drawn from eight government/public senior secondary schools in Udi education zone. Nine schools were randomly selected from the 227 schools. A total of 342 senior secondary II school (SSII) students made up the sample of the study. A 20-item students' stereotype self-concept questionnaire (SSSCQ) was adapted from Marsh's Self Descriptive Questionnaire II (SDQII), and a 10-item students' mathematics achievement test (SMAT) was developed by the researchers after reviewing related literature. This was done with the help of experts in the areas. The instruments were face and content validated and used for the collection of data. In analyzing the data, mean and standard deviation were used in answering the research questions while a t test was used in testing the four hypotheses. The findings of the study indicate that gender stereotype has significant influence on students' self-concept and academic achievement in favor of the male students. On the other hand, school location has significant influence on academic achievement of students but has no significant influence on students' self-concept.Keywords self-concept, gender, gender stereotype, academic achievement 2 SAGE Open is associated with the development of beliefs concerning the traits supposedly possessed by most members of a society. It is an exaggerated belief that members of a group have certain traits that are peculiar to them. This implies that the impact of stereotype tends to change the individual's perception of reality over a period of time. Stereotypes are widely held beliefs about the character and behavior of all members of a group. Stereotyping is the perception, clarification, and assessment of social objects (events) on the basis of specific notion (Ramalingam, 2006). A stereotype is a rigid, simplistic caricature of a particular group of people, which in one way or the other can affect individuals by limiting them on their academic achievement (Kauchak & Eggen, 2011). From this evidence, it is possible that stereotype might limit children from pursuing their career choices. Stereotype becomes a problem when forces in schools and the society limit the academic potential of either male or female. According to Francis and Skelton (2005) and Wessel (2005), gender stereotypic views create negative influence on children in their choice of career decision, and females are less likely to study engineering and computer sciences than males. Therefore, there are some indications that gender stereotype can influence individuals' academic perceptions and achievement.Ryan and Adams (1999) developed a general model called the "family school relationship" (FSR). They proposed that those features of the child or family that have the most immediate co...