Strengthening mental health nurses' (MHNs) resilience may help mitigate the negative effects of the emotional labour (EL) of their work. There is no prior evidence on MHNs' experiences of resilience in the context of EL. This interpretive qualitative study sought to explore how MHNs build and maintain their resilience in the face of high levels of EL. Semi-structured interviews were conducted with 11 MHNs. Reflexive thematic analysis was used to analyse the data. Four main themes were constructed. The first three; Being attuned to self and others, Having a positive mindset grounded in purpose, and Maintaining psychological equilibrium through proactive self-care, describe how MHNs build and maintain their resilience. The fourth theme, Running on emotionally empty, describes what impedes MHNs' resilience. MHNs engaged in internal self-regulatory processes to manage their mental and emotional state. They maintained intra- and inter-personal boundaries and proactively used self-care strategies to maintain their well-being. Through this, they were able to replenish and sustain the energy required to maintain a state of equilibrium between themselves, their interpersonal practice, and their working environment, and to positively adapt to EL. However, lack of organizational support and high workplace demands can negatively impact MHNs' equilibrium and adaptive ability. There is a need for organizations to proactively work to reduce workplace stressors, and support MHNs' professional well-being and practice. Education and support strategies focused on strengthening MHNs' resilience, well-being, and mental health practice capabilities, including the provision of clinical supervision, and clear role expectations within MHNs' scope of practice are recommended.