Teacher cognition, i.e. what teachers know, believe, and think (Borg S, Teacher cognition and language education: research and practice. Bloomsbury Publishing, 2006) and how these mental processes influence their instructional practices, is a fundamental issue in language education. The incorporation of technology into language teaching has provided teachers with innovative resources and methodologies and influenced their cognitive frameworks, pedagogical strategies, and professional development. This entry first provides an overview of the concept of teacher cognition, tracing the transition of its conceptualization from a predominantly cognitivist framework to a more comprehensive sociocultural perspective. It then discusses how technology integration into language education influences teachers’ thought processes and classroom practices. Finally, it argues that the evolution of technology into AI will redefine educational technology and teachers’ thinking processes, leading to transformation of AI from a technological tool to an active participant in the teaching process. This shift aligns with the notion of distributed cognition (Hutchins, 1995), where AI and teachers collaboratively enhance the learning experience. To promote more adaptive, responsive, and efficient classroom practices, further research should address the complexities of teacher cognition in the digital era and bridge the gap between teacher cognition and student learning.