<p>Given an upsurging number of studies on teacher identity in the past decades, a critical evaluation and synthesis of the quantitative instruments would provide strong support to better understand the complexity of teacher identity. We reviewed 37 existing self-report scales published between 2000 and 2024 to synthesize the domains of teacher identity. Results indicated that 21 studies failed to develop operational definitions for teacher identity, and 27 studies made no reference to a theoretical foundation in the scale development. A scrutiny of the psychometric properties of the studies reflected a generally good reliability and validity of the scales. Construct validity was examined in 25 studies, but evidence of content validity and criterion validity was missing in 22 and 33 studies respectively. All items in the reviewed instruments were well mapped onto the four domains in the DSMRI framework, and new domains (i.e., “professional orientation”, “emotional orientation”, “ethical orientation”, “intrapersonal experience”, and “empowerment”) emerged in this process. Our results called for a well-defined identity framework when developing instruments for teacher identity and rigorous analytic techniques of measure development to ensure conceptual and methodological soundness.</p>