This study aimed to investigate the common thinking styles based on Sternberg’s mental self-government theory among students of the Imam Abdulrahman Bin Faisal University, Saudi Arabia, according to gender, academic achievement, and extracurricular activities. The descriptive approach was suitable for achieving the study’s objectives. The study sample consisted of 515 students (257 males, 258 females). The researchers developed an Arabic version of the Thinking Styles Inventory. The results showed that the most common thinking style among students is legislative, followed by the hierarchic, judicial, and external styles to high degrees, while the oligarchic, internal, conservative, and anarchic styles were less common at moderate degrees. The legislative style was more prevalent among female students than male students. Students with acceptable academic achievements most used legislative and executive thinking styles, while students with excellent achievements most used the judicial style. The results indicate that students with strong participation in extracurricular activities most commonly use legislative and judicial thinking styles. The study recommends paying more attention to the thinking styles of a new generation of individuals (males and females), who have creative potential, and increasing consideration of extracurricular activities due to their importance in shaping the students’ personalities and meeting their interests and needs.