STATE - OF - THE - ART ARTICLE TESOL teacher educators in higher education: A review of studies from 2010 to 2020 Rui Yuan 1 *, Icy Lee 2 , Peter I. De Costa 3 , Min Yang 4 and Shuwen Liu 1 1 University of Macau, Taipa, Macao, 2 The Chinese University of Hong Kong, Hong Kong, Hong Kong, 3 Michigan State University, East Lansing, Michigan and 4 National Chung Cheng University, Minhsiung, Taiwan *Corresponding author. Email: ericruiyuan@um.edu.mo (Received 29 May 2022; accepted 3 June 2022) Abstract Despite the wide recognition of language teacher educators’ contributions in the field of Teaching English to Speakers of Other Languages (TESOL), research on language teacher educators has only picked up the pace in the last decade, shedding light on their cognition, practices, and identities in relation to various personal, interpersonal, and contextual factors. This article provides a systematic and critical review of 69 empirical studies on university-based TESOL teacher educators from 2010 and 2020. A methodological review was also conducted to analyze the different research approaches employed by previous researchers. A synthesis of the identified research led to four major themes, namely: (1) a general professional state (including responsibilities, challenges and quality), (2) professional engagement (including teaching, prac- ticum supervision, and research and publishing), (3) cognition (including beliefs, knowledge, and expert- ise), as well as (4) continuous learning and identity development. Through a critical discussion of the themes, the review argues against the implicit yet powerful discourse that characterizes language teacher educators as ‘supermen/superwomen’ and emphasizes the need to humanize them as whole people by rec- ognizing their unique strengths and struggles as well as diverse learning needs. The review also proposes a new research agenda to stimulate and deepen future investigations on language teacher educators in TESOL. 1. Introduction Teaching English to Speakers of Other Languages (TESOL) teacher educators and their work are vitally integral to the operation and development of second language teaching and teacher education (Barkhuizen, 2021; Yuan & Yang, 2022). Working as scholars, practitioners, and researchers (Peercy & Sharkey, 2020), they constitute the main force for preparing and developing language teachers at pre- and in-service levels in a wide range of English as a Second or Foreign Language (ESL/EFL) contexts where language teacher education (LTE) is often housed in higher education institutions (Yuan & Lee, 2021). Back in 2010, Tony Wright published his seminal article in Language Teaching, which analyzed the existing studies on policies, practice, and innovations in LTE. While Wright acknowledged the crucial role of language teacher educators in modelling effective teaching practice and facilitating language teachers’ reflective engagement, he pointed out a lack of research and reflection on the lived experi- ences of teacher educators who need to engage in continuous learning amidst the rapidly shifting and potentially challenging landscape of LTE (Deroo et al., 2020; Peercy et al., 2019). In other words, who language teacher educators are, how they practice and develop, as well as what impacts they have on language teaching and learning have remained a ‘black box’, which urgently calls for research attention. Since then, there has been a steady growth of literature on this topic. Drawing on a variety of research methodological approaches, TESOL researchers and practitioners have © The Author(s), 2022. Published by Cambridge University Press Language Teaching (2022), 1–36 doi:10.1017/S0261444822000209 https://doi.org/10.1017/S0261444822000209 Published online by Cambridge University Press