The teaching and learning in Indonesian elementary schools focus both on students' concept mastery and character development. Teachers are encouraged to implement a learning model that integrates character values and yet promote learning interest. This study was aimed at investigating the mathematics learning interest of grade three elementary school students through the integration of thematic learning with character education, referred to as the character-integrated thematic learning model. Using a quasi-experimental pretest-posttest control group design, this study involved 70 students and employed a questionnaire to obtain data, which were analyzed using descriptive and inferential statistical techniques. Descriptively, the average scores of students' learning interest before and after the implementation of the character-integrated thematic learning model are respectively 117.54 and 140.69 with the gain index of 0.44 in the fair category. While score obtained for thematic learning model are 116.11 and 120.23 with the gain index of 0.07 in the low category. The results of the statistical inference analysis using the independent sample t-test were obtained t-count of 4.98 > t-table of 1,667. This indicates that there has been a significant increase in students' learning interest scores with the implementation of character-integrated thematic learning model. Thus, this learning model can be applied to pay attention to the development of student's character which has an impact on increasing student's learning interest.