Trigonometry is often perceived by university students as an abstract and challenging branch of mathematics, largely due to conventional teaching materials that rarely connect concepts to real-life contexts. This gap frequently results in low levels of critical and creative thinking among students, as they tend to memorize formulas rather than construct meaningful understanding. This study aims to examine the effect of a contextual trigonometry e-book on students' critical and creative thinking ability. A quasi-experimental method with a nonequivalent control group design was employed, involving students divided into an experimental group, taught using the contextual trigonometry e-book, and a control group, taught using conventional materials. Data were collected through pretest and posttest instruments measuring critical and creative thinking skills, and analyzed using inferential statistics (independent sample t-test and N-gain score analysis). The findings reveal that students who used the contextual trigonometry e-book demonstrated significantly higher improvement in both critical and creative thinking ability compared to those in the control group. The e-book's contextual approach, which integrates real-world problems relevant to students' daily experiences, was found to stimulate deeper conceptual understanding, logical reasoning, and innovative problem-solving strategies. These results suggest that contextualization in digital learning materials plays a crucial role in bridging abstract mathematical concepts with practical application, thereby fostering higher-order thinking skills. In conclusion, the contextual trigonometry e-book proves effective in enhancing students' critical and creative thinking ability and can serve as an alternative instructional resource for mathematics education in higher education institutions.