This paper extends our understanding of agency in second language (L2) students' academic English socialization by reporting on an investigation into how two mainland Chinese doctoral students enacted their agency in feedback-seeking for improving academic English writing during their studies in an English-medium university in Hong Kong. The findings show that the ways in which they exercised their agency to seek language feedback from socializing agents varied between individuals and in different feedback-seeking contexts. In particular, their enactments of feedback-seeking agency are found to be differentially shaped not only by their academic writing goals, but also by the habitus derived from their past experiences and the forms of social and cultural capital they accumulated prior to and during their doctoral studies. The findings also reveal that their language ideologies regarding the role of native-speaker norms in academic English writing mediated their feedback-seeking agency by exerting influence on their academic writing goals and their perceptions of different socializing agents as affordances for their language socialization. Overall, this paper offers more nuanced understandings of agency in L2 students' academic English socialization and illustrates the complex and dynamic interplay between agency, goal, habitus, capital and language ideology in shaping their feedback-seeking behaviour. Copyright © 2023 Routledge.