This study aimed to investigate how the community-based socioscientific issues program (SSI-COMM) affected middle school students' sense of place (SOP) and character development as citizens. We designed and implemented SSI-COMM on fine dust, abandoned pets, and recycling issues that were closely related to the students' local communities. SSI-COMM consisted of four phases, and in each phase, students engaged in various activities both within and outside of school. A total of 441 seventh graders participated in SSI-COMM over 8 weeks. Two questionnaires were used to measure the changes in students' SOP and character development (CVGCA) through SSI-COMM. Paired t test was used to compare the effects of SSI-COMM on SOP and CVGCA. In addition, hierarchical cluster analysis was conducted to identify and describe the students who showed similar patterns based on score changes in SOP and CVGCA and to create student profiles to investigate how to appropriately target those students to develop their SOP and CVGCA. The results indicated that students' SOP and CVGCA scores improved after the students participated in SSI-COMM. In detail, a 6-cluster option was determined to provide the best representation of the data measured before and after intervention (groups A to F). Although there were some differences in the pattern of score change among groups, four groups out of six groups (groups A, B, C, and D; about 69%) showed a positive change after implementing SSI-COMM. SOP scores were found to be statistically significant in all groups except group E, and CVGCA scores were statistically significant only in groups A, B, and C.