The unbalanced development of peri-urban environments and the intensification of spatial segregation are major challenges in urban planning, potentially leading to inequalities in access to services, an uneven distribution of facilities, and horizontal urban expansion. In this context, the urban infill approach, which emphasizes the efficient use of a city's internal development capacity, can serve as a strategy for guiding spatial development and reducing pressure on peripheral lands. This study aims to develop a model of balanced development in relation to spatial segregation in peri-urban environments through an urban infill approach, focusing on settlements surrounding Tabriz, Iran.This applied research employed a spatial analysis approach. The conditions of 12 peri-urban settlements were evaluated using eight selected indicators covering access to urban services, public transportation, land-use mix, access to employment opportunities, green-space provision, balanced building density, land-use changes, and physical development pressure. The Ordinal Priority Approach (OPA), based on expert judgments, was used to determine the relative importance of the indicators, while the Shannon entropy method was applied to assess their information dispersion. Spatial analyses and assessments of physical development changes using Geographic Information Systems (GIS) provided the basis for developing the final model.The findings indicated that spatial access to urban services, with a weight of 0.2585, and access to public transportation, with a weight of 0.2397, had the highest relative importance in evaluating the settlements. In the final ranking, Kojoovar ranked first with a score of 0.8761, while Chavan ranked twelfth with a score of 0.4196,