Exploring Cultural Diversity Portrayed in ELT Textbooks for Public Secondary Schools in Chiang Mai, Thailand

Globalization has elevated the status of English worldwide, prompting significant shifts in English Language Teaching (ELT). This study examines the representation of cultural diversity in ELT textbooks used in Thai public secondary schools, emphasizing the growing importance of culturally inclusive content. Specifically, it analyzes four key components—pictures, reading passages, communicative activities, and grammar practices—to evaluate how cultural diversity is portrayed and whether such content supports integration into English classrooms. The sample includes three Ministry-approved textbooks: New Frontiers 1, Spark 1, and New World 1. Findings reveal that content from non-native English-speaking contexts is prominently featured, offering substantial exposure to global cultures. Some materials also incorporate elements of Thai culture, particularly in reading passages and communicative tasks. However, the move toward fully embracing intercultural and multicultural perspectives across all textbook components remains inconsistent.