As a group, English Language Learners (ELLs) are diverse and come from a variety of home languages, cultures, educational backgrounds, and educational needs. This brief focuses on descriptive characteristics of the ELL students served by the School District of Philadelphia in 2014-2015. Specifically, this brief highlights the diversity of the ELL population in three key characteristics that impact schools' resource needs and program decisions: ELL population concentration, linguistic diversity, and English language proficiency levels.